Did the USSR Share Atomic Secrets with China?
By Evgeny A. Negin and Yuri N. Smirnov
On the day of the first Chinese atomic test on 16 October 1964, Prime Minister Zhou Enlai reportedly said with a smirk: "Let it be our parting salute for Khrushchev." The poisonous phrase revealed glee: two days earlier the detractor of Stalin whom the Chinese leadership hated so much was sent into forced retirement. But "the salute" was linked to Nikita Khrushchev in yet another direct way for another reason: Earlier the Soviet leadership helped China to build its own nuclear weapons.
Only the uninitiated can believe that "China has not received Soviet atomic know-how."  In the words of Khrushchev's son Sergei, two years passed after "the agreement signed in 1957" when "father for the first time felt deep fissures in "fraternal friendship." He began to think for the first time if it would make sense to pass state-of-the art military technology, to teach the Chinese how to produce rockets and nuclear charges." Sergei Khrushchev continues: by May 1959 N.S. Khrushchev "finally concluded: under no circumstances should we transfer atomic secrets."  . In other words, it looks as we were only about to share our secrets, but at some moment, before crossing the line, we changed our mind. In reality, beginning in 1957 the work went on full steam ahead and only later somewhat slowed down, and then ceased completely.
These two years did not pass without trace. Soviet specialists, including the designers of nuclear weapons, went to China and worked there on the instructions of the central party organs. They shared their expertise with Chinese colleagues. Of course, China did not receive a real nuclear bomb, the finished device. This was never set as a task. We had to train Chinese specialists, to assist them in establishing their own industry. And this was carried out on full scale according to the instructions received from the Soviet leadership, and precisely according to its timetable, until the program of cooperation between the USSR and China was terminated. This assistance, incidentally, encompassed not only know-how, but also the equipment.
We will not turn to the memoirs of Khrushchev to prove our point. He dictated them from memory, without documents and reference literature, when he had long been out of office. Instead, we will cite an excerpt from his conversation in October 1964, a few days before his retirement, with Japanese politician [Aiichiro] Fujiyama. Anastas Mikoyan also participated in this conversation 
Khrushchev: "The Chinese can stage a nuclear explosion. At the moment when our relations were close and fraternal, Chinese scientists had access to very many of our secret works, and they saw how we do t... We gave them the equipment for the production of atomic fuel... Thus they gained quite a lot from us and know a lot what to do."
Mikoyan added: "We assembled plants for the Chinese and provided them with other kind of assistance."
This program of assistance was designed in the years where the relations between the Soviet Union and China could be best described in the words of the song that was popular even in Stalin's time: "Moscow-Beijing": "The Russian and the Chinese are brothers forever... " It seemed that the friendship sanctified by the same ideological choice, would be unbreakable. It seemed much more solid than the ties that emerge between countries on the ground of sober pragmatic interests. Chinese youths arrived to the main cities of the Soviet Union by trainloads and absorbed knowledge at the best universities and institutes of our country. Chinese fraternities were most populous. And the groups of Chinese students at physics classes, particularly on the chairs of atomic physics, were the largest. At that time thousands of Chinese specialists and military had their training at the plants and factories of the USSR, at various research institutes, as well as in military academies. Thousands of Soviet specialists went to work in China.
In 1957 the moment came when the Soviet leadership decided to open for the Chinese friends the secrets of the most closed and protected atomic ministry of the country - the Ministry of Medium Machine Building.
Speaking before the 20th congress of the CPSU on 14 February 1956, Khrushchev stressed: "Our country gives assistance to People's Republic of China in construction only during one five-year plan of 156 plants and 21 separate workshops... We will continue to provide mutual all-sided assistance in developing economy, technology, science and culture. Therein we see our fraternal duty before the socialist camp."  . Next day the head of the Chinese delegation at the Congress Marshal Zhu De welcomed "friendship and unshakable unity of the two great states of China and the Soviet Union that grows stronger every day." He remarked that "the construction of socialism in our country on such a giant scale and at such a speedy is inextricable from the unselfish, all-sided and systematic assistance from the Soviet Union."  . Three years later Zhou Enlai spoke to the 21st Congress of the CPSU and also expressed gratitude for "continuous fraternal assistance to China." But while Zhou insisted that "there were no forces in the world that could undermine our great internationalist solidarity"  , Khrushchev in his report to the same Congress on 27 January 1959 already mentioned "some false rumors about allegedly existing differences between the Communist Parties of the Soviet Union and the Chinese Communist Party." 
Discord came to the surface, and during the last meeting between Khrushchev and Mao Zedong in Beijing on 2 October 1959 there was so much heat that Khrushchev had the following verbal exchange with Marshal Chen Yi  :
Khrushchev: "I drew your attention only to specific oversights and never hurled at you basic political accusations, and you put forth precisely a political accusation. If you consider us time-servers, comrade Chen Yi, then do not offer me your hand. I will not accept it."
Chen Yi: "Neither will I. I must tell you I am not afraid of your fury."
The brief and dynamic period between the middle of 1957 and 1959 that saw the spectacular rise of the "unshakable friendship" and its precipitous collapse down to outright enmity was also the period of cooperation of Soviet atomic scientists with Chinese colleagues.
There were international precedents to the atomic cooperation and transfer of atomic secrets by the Soviet Union to China. On 16 June 1940, during the German occupation of France there was the decision to transfer to British authorities the valuable materials from the laboratory of Frédéric Joliot-Curie, including 185 kilograms of heavy water, so that the experiments of French atomic scientists could be continued in Great Britain  . Moreover, Americans admitted that the research works of British scientists that, in their turn, had been stimulated by the contribution from the French, gave an impetus for the decision in the end of 1941 to begin in the US the works on the construction of atomic bomb  . At the end of 1941 and in early 1942 American and British scientists organized exchange of opinions on the problem of chain reaction in uranium. In the summer of 1942 the British, seeking to alleviate their financial burden, decided to transfer to the Canadian authorities a group of scientists that worked on the creation of the reactor on heavy water. At last, in August 1943 in Quebec the governments of the US, UK and Canada signed an agreement on cooperation in atomic area. Its text was published only in 1954. According to this agreement some of the best physicists of Great Britain, among them M. Oliphant, J. Chadwick and Rudolf Peierls, assumed leading positions in various branches of American atomic enterprise, i.e. at Berkeley, Oak Ridge and Los Alamos  . Incidentally, these and other British physicists, among them Klaus Fuchs, returned from the US to Great Britain and, having rich information and experience acquired during the creation of American atomic bomb, started working in the British atomic project that led to success only in October 1952.
The transfer of atomic secrets by the Soviet Union to China stemmed from the allied commitments. But it had one significant particularity. Unlike nuclear cooperation among Western powers during World War II inspired by the needs and conditions of war, the Soviet leadership took its decision under the spell of ideological rapprochement with China. There were no obstacles of international legal nature at that time; the international non-proliferation treaty was only conceived ten years later and came into force in 1970.
Euphoria and Hangover
The dynamics of events was especially impetuous by the middle of 1957. In the spring the head of defense department of the CC CPSU Ivan D. Serbin called to his office Evgeny D.Vorobyev, a scientific director of Chelyabinsk-40 and one of the closest assistants of Igor V. Kurchatov. He was among the permanent staff at this highly important atomic plant, beside its director, chief engineer and the representative of the secret services, who had top clearance. As Vorobyev recalled, "Ivan Serbin told me that the leadership had decided to pass onto China the know-how of production of nuclear weapons. In his words this, naturally, should be carried out step by step. A scientific nuclear center will be created near Beijing that will quickly train specialists in various fields, from the diffusion isotope separation to all kinds of things related to reactors, physics and radiochemistry. The industrial part, including geological exploration and extraction of uranium, will be the fiefdom of Zadikian as an advisor [Arshak A. Zadikian, chief engineer of one of the Chief Directorates of the Ministry of Medium Machine-Building, worked in China from 1956 to 1960]. My assignment was to become a scientific adviser in the planned center and to focus my attention on reactors, methods of separation of isotopes, the related physics and training of specialists in all these fields. The issues of chemistry and radiochemistry were assigned to Sergey A. Zakolupin who worked under Andrey A. Bochvar [who was in charge of the metallurgy of plutonium]. Serbin suggested I should think about his proposal and come back for another meeting in a month. After a month I finally decided not to go to China. I also felt that Igor Kurchatov was not enthusiastic about my assignment."  But Vorobyev had to go; he stayed and worked in China from May 1957 till November 1959.
By the moment when the nuclear center near Beijing was organized, Chinese leaders had plucked patriotic tunes to their former compatriots and invited home a number of highly qualified Chinese researchers-physicists who worked abroad in big laboratories and were rather closely in touch with nuclear subjects. In this way they were able to create a nucleus of young people who gradually assembled at that center.
When Vorobyev arrived to China, he found there were around 60 such specialists at the Chinese center. By the end of 1959 the collective grew, largely because of the inflow of young people and reached 6000.
At first Vorobyev's main task was to train young researchers of the center in the areas that would ensure technological backup for production of fissionable materials - enrichment of uranium and accumulation of plutonium. At that time only the foundation for the first Chinese experimental reactor had been finished. The construction had to be completed, the reactor had to be physically launched and be brought to the planned yield. The first load for the reactor came entirely from the Soviet Union. The laboratories of the diffusion method of isotope separation also received from the Soviet Union "tail machines," i.e. equipment that procured the highest enriched uranium.
Everything had to be organized. The work began with designing the teaching curricula. Vorobyev's office was located in the "Second ministry," which was in charge of the atomic problems. As the center was being completed, he received an office there as well. The Chinese physicists who returned to China from abroad did the lecturing.
"I served in the role of a conductor," continued E.D. Vorobyev, "and, although I did not lecture myself, I trained a group of people. We had very substantial conversations. More than with anybody else I worked together with Professor Qian Sanqian who had previously worked at the University of Paris under Joliot-Curie. This energetic, intellectually focused and dedicated man with European education led an atomic program similar to the way Kurchatov did it in our country. Qian Sanqian was in very close cooperation with me. In effect, he composed draft plans for work of the entire institute and came to me with them. We worked together a lot and he came to me very often. We also met at his place. He was a leader of high rank, but I did not see bodyguards near him. He was a very decent person. Incidentally, Qian Sanqian used to attend the sessions of the United Institute of Nuclear Studies at Dubna as a plenipotentiary representative of China. I also was in close contact with Zhou Enlai who was the supervisor of all foreign specialists. He was a very bright, energetic and self-reliant man. The first critical assemblies at the experimental reactor were carried out under my direct guidance. We did many of them, and this was the best form of training for the personnel. During this operation, people immediately felt the nuclear reactor "with their guts", how it behaved, and how it reached the critical stage. We, a group of Soviet specialists, did so to speak fine-tuning for the center. We completed its construction to the last detail. The center helped to bring up the cadres. At the functioning reactor (on heavy water) they could produce small quantities of plutonium. "The tail machines" for the diffusion method of isotope separation, transferred by our country, allowed them to enrich uranium."
The inauguration of the completed nuclear center near Beijing took place in 1958. First deputy minister of medium machine-building Dmitriy V. Efremov came to the celebration. His program included a visit to Mao Zedong. This meeting was a shock for the unsuspecting Efremov. He returned to the hotel in a state close to collapse. He lay on a sofa. It was obvious that he had lived through something terrible, and he could not yet come to terms with what had happened. It turned out that Mao, when he found during the meeting that Efremov had received instructions from the leadership to clarify Soviet policy regarding the Taiwan crisis, the Chinese leader suddenly appeared as the man who dictated his iron will to everyone else. He did not let Efremov say another word and spoke all the time. From that moment on, when he addressed Efremov, he used instead of "comrade" the unusual "foreigner." Efremov said immediately after the meeting that Mao underlined, although in a delicate form, that he was treating him as an alien. For half an hour Mao, in effect, bullied and taunted his interlocutor. Efremov realized that it was the beginning of some kind of large and ominous process and was upset that perhaps he had committed some error...
There was no error. It was revealed later that at the secret meeting (as the Chinese insisted) between Khrushchev and Mao Zedong at the end of July 1958 in Beijing the relationship between them, despite outward assurances of friendship, was already tense. 
This is How the Atomic Bomb is Made...
A little earlier than the summit in Beijing, on 18 June a group of Soviet designers of nuclear weapons from Arzamas-16 arrived to Beijing. They stayed in China for a month and a half and returned home on 2 August 1958. Incidentally, by that time the Soviet Union had already built atomic and nuclear weapons and carried out 62 tests  .
The talks on the trip to Beijing went through Nikolay I. Pavlov, the head of one of the Chief Directorates of the Ministry of Medium Machine-Building. He telephoned Evgeny A. Negin who then was the first deputy of the scientific director and the chief designer of the nuclear center in Arzamas-16 [i.e. of Yuly B. Khariton - transl.], and invited him to travel to Moscow "to discuss one issue that has just popped up."
At the meeting Pavlov told Negin in a strictly confidential, face-to-face conversation, that our relations with China reached such a level when we should go to the Chinese comrades and tell them what nuclear weapon is. They want to build a bomb and we should tell him how it is made. The delegation assigned to go included E.A. Negin (the leader), chief designer of the "serial plant" Nikolay G. Maslov and theoretical physicist Viktor Yu. Gavrilov from the theoretical department of Yakov B.Zeldovich. (Gavrilov frequently went to the test site and knew all the range's proceedings very well. He tried hard to look like Kurchatov, known as "the Beard." He mimicked his intonation, his gestures, therefore the military from the testing range called him "The Little Beard."
The plan was that after a month-long tour of duty Gavrilov would stay to provide further assistance for the Chinese specialists. But later, it was decided to send instead of Gavrilov another man as an adviser in China. It was Boris N. Ledenyov, the head of gaseodynamic division of the nuclear center in Arzamas-16, who worked in China from 1958 until 1960.
As was the custom, before the trip to China one had to work out precise instructions and obtain the minister's approval. The prepared draft went to Pavlov who liked it and reported it to minister Efim P. Slavsky. The reaction of the minister was favorable. But strangely, when the delegation came back from China, it was learned that the Minister had never signed the instructions.
When the delegation arrived in Beijing, it was hot and incredibly humid. The Chinese took the delegation to a hotel, but did not seem to realize who had come to them. In any case, when the Soviet specialists gave their first talk and spoke in great detail about technical aspects of the problem without mincing words, there was such a big crowd, that the guests smelled a violation of secrecy regime and expressed their surprise. A head of one of the Chief Directorates of the Second Ministry tried to reassure them: "What is wrong? They are all party members... " It sounded as if you were a party member, you must be entitled to clearance to know nuclear secrets. Still, after some manipulations the number of listeners shrunk, approximately by half.
After this talk there were conversations about what the Chinese actually wanted from their guests. At the same time the guests learned that the Chinese still had no equipment for the production of nuclear charges.
The first businesslike session was conducted by one of the leaders of the Chinese nuclear project, Liu Qie - deputy minister, later he became minister of the Second Ministry, a very polite and exquisitely tactful man.
There were three questions to the guests: how does our design bureau, Arzamas-16, look from the organizational viewpoint, and how is industrial coordination organized in the nuclear field; how was the atomic bomb made; and finally, how to test these bombs on the test site.
The Soviet guests told the Chinese about the structure of the bureau and about the order in which specialized complex components had to be received in the overall scheme of cooperation for the assembly of nuclear charges. The Chinese remarked that "we will have an even larger cooperation." They asked the guests to look at some of their plants and advise them about what could be produced there for the nuclear project. For that reason, during the first half of their stay in China, our specialists were busy traveling. They visited the plant that produced various barometric devices, the radio plant and the plant that produced artillery pieces from Soviet blueprints. The Chinese showed other plants as well (including the ones they had not completed at that moment) and also the blueprints of a giant assembly line where one could work on the bomb. Before the return of the delegation to the USSR, this building was already completed and looked extremely impressive. One should note that in general all the construction works the Chinese did were accomplished fast and with an extra capacity. Also they were very smart in taking advantage of the assistance by various socialist countries in various industrial fields: they picked the best options and hired very good specialists.
As it was agreed in Moscow, each of the participants on the delegation was responsible for lecturing on his subject. The decision was taken to initiate the Chinese into the making of the Soviet atomic bomb tested in 1951. The first device detonated by the USSR in 1949 was regarded as already outdated. But, at the same time, the leadership declined a proposal to share with China a more advanced device than the 1951 bomb.
Gavrilov told the Chinese about the general physics of the bomb, paying special attention to the physics of the blast wave and critical mass.
Negin informed them on the design of the explosive charge of the atomic bomb and the principles used in its construction. Of course, he disclosed the principle of implosion and how it is realized. He covered everything from "the top" of the explosive charge, i.e. the casing, down to the neutron fuse. He said where they should avoid gaps and clearances. Virtually everything. He only omitted the measures of tolerance and allowance and did not give any documentation. Instead, he just drew the design scheme on the board.
Maslov used the drawn scheme of the charge and "encased" it in a ballistic case. He talked about the bloc of automatic machinery, where and what kind of devices are located, how they function and what they are for.
The presenters told pretty much everything they knew and what they were authorized to tell.
Naturally, the Chinese asked questions. Incidentally, the questions arose mainly by the end of the reports, when the audience already began to have certain images in their heads. For instance, they asked Maslov, how many machine tools they must order. He responded: 650. The listeners inquired from him on details, listened very attentively and wrote down what he said. They seemed to have a decent level of engineering education. They asked direct questions and obtained direct answers.
But the Chinese did not limit themselves to questions. They said that they might make errors in their writings and cause misperceptions. And then, they said, it would be impossible to get back to the reporters. Therefore the guests had to write a lot themselves, on the device and other issues.
Not only the leading figures of the Chinese nuclear project attended the conversations. Once came a lean, dark man with graying hair and very bright eyes. All the Chinese generals present stood up to attention, as one man. All this looked rather comical, since this man was dressed in silk training pants, shirt and slippers on bare feet. He looked almost like a man who just came from the bath. It turned out that it was marshal [Zhu De], chief of the General Staff of the Chinese Army. He nodded, inquired what class was going on and, not willing to disturb, quickly left.
"Are You All Crazy?"
Meanwhile, as the designers of nuclear weapons still stayed in China, Arzamas-16 prepared the next phase of the program. In the cul-de-sacs of one of the plant here, at the order of the minister, one would soon see two or three sealed railroad cars that were under constant guard.
In one of the cars was the model of the same bomb the design of which had been the subject of conversations in China. Others contained full documentation not only of the bomb itself, but also of the test benches, control panels, all kind of equipment, rigging, testing devises, experimental blocs... All was in order. The only peculiarity was that all the patterns on the blueprints had the names of their authors cut out.
The cars kept standing. From China Ledenyov sent requests for this documentation. And, after half a year had elapsed, somebody from the heads of directorates of the Ministry of Medium Machine-Building decided to check on this with first deputy minister Aleksandr I. Churin: "What should we do? There are cars, stuffed with documents, with the model of the device... And there is no command to dispatch. Should we wait any longer?" The minister was absent and Churin called the Old Square [i.e. the Central Committee of the CPSU].
The party leadership was vehement: "What bomb?! Where to send it?! You must be crazy in the ministry?! And Minister Slavsky does not know anything?!" Churin replied: "Efim Slavsky is absent and nobody can be made responsible."
"Don't even think of dispatching! Tell them to destroy it immediately!"
After this, the whole documentation was burnt, the cars were pulled away, the guards were dismissed. Thus, the documentation did not reach China.
During our visit to China, the Chinese asked about the testing range. Gavrilov, who was very familiar with this topic, told them "what, how and why." However, he stressed that the testing range was under the supervision of the Ministry of Defense and for more substantial talk the Chinese should address the specialists from this ministry. The Chinese did not wait long to do so. As a result, they visited the Soviet atomic testing range, and saw everything there "live," including the device. Moreover, at the end of November 1958 two officials from the Central Research Institute [TsNII] 12 of the Ministry of Defense - deputy head of the Institute's department Colonel Fyodor K. Burakov and Lieutenant Colonel Ivan A. Razmyslovich appeared in the Harbin military engineering-technical academy as military specialists.
Burakov recalls that by early 1959 he and Razmyslovich developed a program of a course on the protection of troops against atomic weapons. The text of every lecture they "developed and wrote down in a classified notebook. From the secrecy department, the text of the lecture went to the translator; then there were consultations with professors and the text was returned to the experts. The content of this work reflected changes and fluctuations in the general state of relations with China. The instructions from the top to the experts varied from "give them everything," to "do not elaborate too much." In August 1959 General Guan Dung during a meeting in Beijing said that he knows where I worked, for he had been to the research center [NII] in Zagorsk (near Moscow) where the Chinese delegation "had seen everything."  . During the conversation with another Chinese military leader Burakov noticed on his desk "the general scheme of Semipalatinsk test site with all the installations and photocopies of the test benches with details" of some devices from Zagorsk.
The unfortunate meeting between Khrushchev and Mao Zedong in Beijing at the end of July 1958 left its imprint on the program of the visit of Soviet nuclear designers in China. At the Soviet embassy they heard: "Khrushchev has left, and it is time for you to pack your suitcases." By that time the delegation had already fulfilled whatever was feasible in this situation. The Chinese arranged a modest farewell reception, gave them the medals for "Sino-Soviet friendship." Ledenyov, who went after this to China as an advisor on nuclear weapons, attempted to get things for the Chinese from Moscow during his two-year stay, but his efforts took place already during the twilight of Sino-Soviet relations and could not lead to any significant results.
Gradually the activities of Vorobyev in China also became vapid and meaningless. At that time the plan was to transfer to China the blueprints of the industrial reactor. However, according to Vorobyev, he heard from Moscow "in a veiled form, that we would not transfer it right away. The blueprints that came were for a smaller-size reactor, and when I looked at it I realized that it was so small that it could not even start up. Simultaneously the Chinese were greatly interested in atomic submarines and began to walk around me in circles, asking if I could help them. I had to dodge and be 'diplomatic.' I dragged my feet as much as I could, realizing that I could not do it." 
Was it Much or Little?
Those among our experts, who left China before the end of 1959, were showered with honors and thanks, with the medals "Sino-Soviet friendship." The Chinese were generous on promises and, among others, even intended to set up memorials to Soviet military specialists at the Harbin Military Engineering-technical Academy  . Later our compatriots had to run away from China, leaving their belongings behind. They had to live through the humiliating procedure: walking with bowed head, with jeering crowds around them, under the "little red books" of Chairman Mao. It was all the more insulting, that those people were professionals who, far from political intrigues, really helped China and unselfishly shared with the fraternal people their experience and knowledge. In our country the assistance to China was some kind of universal impulse, the expression of sincere trust to another people, when the cause seemed to be big and noble.
One episode is characteristic in this regard. I.V.Kurchatov, when he prepared himself for the Second international conference on the peaceful use of atomic energy (in Geneva in September 1958), wrote a paper on the regulated thermonuclear synthesis and on the construction of the installation "Ogra." He sent this report in early summer of 1958 to E.D. Vorobyev with the order to read it to Chinese scientists. Soon Vorobyev read this paper in the Chinese Academy of Science in the presence of the Academy's President Guo Moruo. Later the paper was published in China.
When the Soviet delegation arrived in Geneva, the Americans there were very upset. They were amazed that Kurchatov's lecture was read in China before it became known to the US scientific community. They even interpreted it as a political demarche  . About that time a group of Chinese physicists appeared in Moscow to work on leave for the Institute of atomic energy there. It is symbolic, that at the same time this Institute sent to China as a gift one of its most impressive and important installations, the so called "Six." It was designed for electromagnetic isotope separation. The entire Soviet technology of isotope separation of lithium had been developed on this installation, and this had an utmost importance for the first Soviet thermonuclear explosion on 12 August 1953. The weight of the magnet of this installation was 250 tons. It was shipped to China along with a vacuum camera and the whole vacuum system, with diffusion pumps, high-voltage power supply and other equipment  .
There is no doubt that during the 1950's China obtained for its atomic project unique information and substantial assistance from groups of Soviet specialists who worked in several Chinese collectives. For instance, according to a report by the Soviet embassy, in 1958 in China there were 111 specialists of the Main Department on the Use of Atomic Energy and 43 geologists specializing in finding atomic raw materials  . A number of authoritative Soviet scientists working on atomic matters (among them Abram I. Alikhanov, Aleksandr P. Vinogradov, Dmitry I. Blokhintsev, Vasily V. Vladimirtsev and many others) came to China for periodic short-term visits. Perhaps this assistance to China would have been more comprehensive had the unity between the USSR and China remained in its initial euphoric phase.
Speaking about the creation of nuclear weapons in the USSR and China, one could find some general parallels, if one compares the importance of the information that our atomic project received from Soviet intelligence, with the knowledge and experience that the Chinese atomic specialists acquired through working together with Soviet scientists and engineers.
Thanks to the intelligence, we received some basic blueprints of the charge and the major basic measurements. As is known, Klaus Fuchs made a special contribution in this regard. Although our specialists already reached the stage of independent discoveries, however, there was still the mystery of how everything functions and how it is made. It took numerous experiments and tests to sort out problems and come to definitive conclusions. After all, we received data from the enemy's center and it was impossible to exclude deliberate disinformation. Therefore, Soviet nuclear designers had to go, with some exceptions, the whole way of developing and fine-tuning the device, from the beginning to the end, as if they had started completely from scratch.
The Chinese were in a more favorable situation. Not only did they receive more data on the bomb, in comparison with what the intelligence had obtained for Soviet scientists, but the Soviet Union also trained Chinese cadres, created the infrastructure for the production of the components of the bomb, and provided assistance in know-how and equipment - all that the Soviet Union had to create itself by relying only on its own resources. Moreover, China obtained the information from a fraternal power, which left no doubt about its authenticity. There would have been the risk of an enormous scandal if the Chinese - in that period of "fraternization" when nobody could yet expect its demise - had found a reason to doubt the information they had been receiving.
Two high-level Chinese participants in the atomic project have published their memoirs: former minister of the Second Ministry Liu Qie and the former head of the State Committee on Defense, Science and Technology, Marshal Nie Rongzhen. Liu Qie recalled that the "strategic decision" that laid basis for the development of Chinese atomic industry was taken by Mao Zedong as early as 14 January 1955. Zhou Enlai, writes Liu Qie, "used the change in the international situation and the favorable opportunity to obtain, step by step, Soviet assistance in the field of nuclear technology. This gave us a chance to master it relatively quickly and allowed to a certain extent to gain time." Nie Rongzhen mentions the visit of Soviet nuclear designers to China "in the first half of 1958" and acknowledges that the basis of the Chinese nuclear power was laid with the Soviet assistance. 
As time passes, the short-lived but fascinating Sino-Soviet nuclear alliance emerges as a most interesting page in contemporary history. Its rich and diverse mosaic included the essentials of the Cold War - the ideological split of the world, the formidable pace of the nuclear age, the mutual trust of people and their yearning for friendship, political cunning and self-interest, as well as deliberate promotion of nuclear proliferation.
(Translation by Vladislav M. Zubok, edited with minor deletions by the PHP, assisted by Yuri Smirnov. Published in cooperation with the Cold War International History Project.)
Lt. Gen. Evgeny A. Negin (1921-1998) worked in the main Soviet center for nuclear weapons research, Arzamas-16, from 1949 to 1998. He was itsadministrative director (1978-1987) and main weapons designer (1959-87).
Yuri N. Smirnov, born 1937, is a Russian nuclear physicist who worked in Arzamas-16 in 1960-63 - first on the Soviet hydrogen bomb, together with Andrei D. Sakharov,. later on underground nuclear explosions for peaceful purposes. Now he is working at the Kurchatov Research Center in Moscow.
 Sergei Khrushchev. Nikita Khrushchev: krizisy i rakety [Nikita Khrushchev: Crises and Rockets], (Moscow: Novosti, 1994), vol. 1, p. 353.
 Ibid., vol. 1, pp. 351-353.
 Archives of the President of the Russian Federation, f. 52, op. 1, d. 597, l. 145, cited in: Dmitri Volkogonov, Sem Vozhdei: Galereia liderov SSSR. vol. 1 [Seven Leaders: The Gallery of the Leaders of the USSR], vol. 1 (Moscow: Novosti, 1995), pp. 411-412. Note by the PHP: According to information received on 3 September 2002 from William Burr, of the National Security Archive, the U.S. Embassy in Tokyo received a substantive account of the Fujiyama-Khrushchev conversation and reported it to Washington on 6 October 1964.
 XX [Twentieth] Congress of the Communist Party of the Soviet Union. Stenographic report (Moscow: Gospolitizdat, 1956) First volume, pp. 13-14.
 Ibid., pp. 226, 228.
 XXI [Twenty-first] Congress of the Communist Party of the Soviet Union. Stenographic report (Moscow: Gospolitizdat, 1959), First volume, pp. 152, 155.
 Ibid., p. 109.
 "Zapis besedy N.S. Khrushcheva 2 oktyabrya 1959 g. v Pekine," Archive of the President of the Russian Federation, f. 52, op. 1, d. 499, ll. 1-33, in: Volkogonov, Sem Vozhdei, p. 414-415.
 David Holloway, Stalin and the Bomb (New Haven: Yale University Press, 1994), p. 57.
 Ibid., p. 82.
 Ibid., p. 80; Richard Rhodes, The Making of the Atomic Bomb (New York: Simon & Schuster, 1986), p. 522.
 Conversation with E.D. Vorobyev. In the private archive of Yu.N.Smirnov.
 Volkogonov, Sem Vozhdei, pp. 412-413.
 Ministry of the Russian Federation for Atomic Energy and the Minisitry of Defense of the Russian Federation, "USSR Nuclear Weapons Tests and Peaceful Nuclear Explosions (1949 through 1990)." Material, originating at Arzamas-16, received by Yurii Smirnov in English translation from a US journalist in Moscow.
 Correspondence with F.K.Burakov. In the private archive of Yu. N.Smirnov.
 Conversation with E.D. Vorobyev. In the private archive of Yu.N.Smirnov.
 Correspondence with F.K.Burakov. In the private archive of Yu. N.Smirnov.
 Private information from I.N.Golovin.
 Vladislav Zubok and Constantine Pleshakov, Inside the Kremlin's Cold War: From Stalin to Khrushchev (Cambridge, MA: Harvard University Press, 1996), p. 227.
 Ekho Planety, no. 24 (September 1988), pp. 27, 28;Izvestia, 11 November 1994. Note by the PHP: In his memoirs, Nie Rongzhen actually minimizes Soviet contribution to the development of the Chinese nuclear program (Inside the Red Star: The Memoirs of Marshal Nie Rongzhen. Beijing: New World Press, 1988. Pp. 683-86, 698-701.)