The history of nuclear weapons is, as David Holloway writes,

at once fascinating and repulsive. It is an exciting tale of discovery and invention, but it tells of weapons that could destroy all life on earth. The history of nuclear weapons in the Soviet Union is doubly fascinating and doubly repellent. Its fascination is enhanced by the mystery in which it has been shrouded for so long. Its repulsiveness is magnified by the brutality of the Stalin regime for which the Soviet nuclear weapons were first created.

The official secrecy surrounding the bomb gave rise to many wild speculations. In 1945, when the Soviets were widely regarded as scientifically and technologically backward, many military people and politicians in the West were convinced that it would take them many years to make an atom bomb. Many scientists knew better, because they had met with Soviet scientists—or at least they did so up to 1937, when the increasing severity of the regime made international personal contact virtually impossible.

During the 1920s and early 1930s natural science made considerable progress in the USSR; this was largely owing to a few leading scientists, including the physicist Abram Ioffe, who founded the Physiotechnical Institute (now the Ioffe Institute) in Leningrad. He also took the initiative in starting similar institutes elsewhere, including a very successful one in Khar’kov. His pupils Iakov Frenkel’ and Nikolai Semenov did much to improve the study of theoretical and chemical physics in the USSR.

In the 1930s physics survived a strong attack by Marxist philosophers, who claimed that they and the Party could decide what was scientific truth. A similar attack led by Trofim Lysenko destroyed Soviet genetics and demoralized biologists. The difference, I believe, is explained by the presence among the physicists of men of great courage and energy, such as Frenkel’, Ioffe, and Igor’ Tamm, and by the absence among them of ambitious charlatans such as Lysenko. Starting in 1937, however, the purges affected scientists; many of the most promising scientists in all fields were arrested and some were shot or exiled. But physics survived.

Nuclear physics, however, was not very strong. After the discovery of the neutron in 1932, and Fermi’s use of it as a probe for nuclei, more Soviet physicists had turned to nuclear problems, but they were frustrated by the fast pace of discoveries in nuclear physics in the West and by delays in communication of scientific developments. Construction of a cyclotron started in the early Thirties but Holloway writes that it was “not until the end of 1940 that it went into normal operation.” The discovery of fission in 1938 by Otto Hahn and Fritz Strassman, and its explanation by Lise Meitner and Otto Frisch in 1939, naturally attracted attention in the USSR, but those who tried to contribute to fission physics felt frustrated for the same reasons. An exception was the discovery of spontaneous fission by Georgii Flerov and his pupil Konstantin Petrzhak in 1940.

There was much speculation in the USSR, as in other countries, about the possibility of a chain reaction in uranium, and about slow neutrons being capable of producing electric power. But most experts thought it would take a long time to put such a system into practice. In any case, research in nuclear physics was suspended in 1941 because most physicists were doing war work.

Still, Flerov felt it was urgent for the USSR to start nuclear research once again, but he failed to convince his colleagues and had no better luck with government officials. He became even more determined, Holloway writes, when he discovered that no new papers about nuclear physics were appearing in American journals; he concluded, rightly, that this meant there was a secret project. In April 1942 he wrote a letter to Stalin about the urgent need for the Soviet Union to have its own nuclear research program.

It is not clear whether this letter by itself would have made a difference, but in the meantime there had been other developments. Soviet intelligence received a copy of the “Maud” Report—the report of a scientific committee to the British government, saying that an atom bomb was feasible—along with comments on the Maud Report by a special government panel. Holloway writes that the “source of this information was almost certainly John Cairncross, the ‘Fifth Man’ of the ‘Cambridge Five,’ who had been recruited as a Soviet agent by Guy Burgess.” The Soviets also had intelligence information about a German nuclear project. This made Stalin think seriously about resuming nuclear research. It was not an easy decision to make in 1942, since the Germans were advancing then into the USSR and the country was in desperate straits. Several scientists were consulted, but without telling them of the intelligence information. In the end Stalin decided to go ahead.

Beria, the head of the secret police, retained overall responsibility for the work, but he remained suspicious of scientists, who would not always think what they were told to think. He also feared the secret information from England might have been planted disinformation.


It was now necessary to put a scientist in charge. Ioffe declined on the grounds of age, and recommended Igor Kurchatov and Abram Alikhanov. Of the two Alikhanov was the better-known physicist but Kurchatov made a stronger personal impression on Stalin and Beria, and he was chosen, a decision amply justified by his later performance. This was in October 1942, and Kurchatov spent the rest of the year making plans and recruiting senior collaborators. These included Alikhanov, Iulii Khariton, Isaak Kikoin, and Iakov Zel’dovich, all members of Ioffe’s institute. They all later took major responsibility for specific sections of the project.

Kurchatov was shown the intelligence reports from Britain, but was not allowed to share them with other scientists. The nuclear-research project was not given the status of a crash program and progress was slow. Experimental work was hampered by the shortage of functioning cyclotrons and other powerful accelerators, and very little uranium was available. If they wanted to follow the British ideas of a reactor moderated by heavy water, they would be held up by the lack of heavy water; and a graphite-moderated reactor, such as the one constructed in 1942 by Fermi’s team in Chicago, would require much more uranium than they could obtain.


A drastic change took place in the summer of 1945. At the Potsdam Conference in July Truman told Stalin about the successful test of an atom bomb at Alamogordo, New Mexico. There is some doubt whether Stalin took in this information. A Russian history professor who was present at the conference as a very junior official told me that he overheard Stalin, on hearing the news, sending a message to accelerate the Soviet bomb project as much as possible. But since this historian’s book contains many serious errors, one cannot give much weight to this evidence. In any case there is no doubt that Stalin understood the implications of the Hiroshima bomb dropped in August. He authorized a crash program immediately, and Kurchatov was told he could have anything he asked for.

By this time Kurchatov had received much detailed information about the Los Alamos project through Klaus Fuchs. His strategy was now to follow the same route that the Manhattan Project had taken. This meant working both on the plutonium bomb and on uranium-235. He knew that a uraniumgraphite reactor could produce plutonium, but some work was also done to develop a reactor moderated by heavy water. Supplies of uranium were obtained from East Germany and from Czechoslovakia. Prospecting for uranium in the Soviet Union was now also pursued energetically, and deposits were discovered in Central Asia; they were exploited by mining operations using prison labor. (“Very few of these prisoners were set free,” Holloway writes, “even after they had completed their sentences.”) Factories were built for extracting uranium from the ore and for converting it to metal. Large quantities of very pure graphite were produced. Experienced managers were appointed to run these and other large-scale industrial activities, but Kurchatov retained control of scientific policy. It testifies to his tact and his ability to get on with people that he had excellent relations with the managers as well as with his scientific colleagues and their staffs.

Kurchatov himself took charge of building the experimental reactor, having worked on the design since 1943. Holloway writes that while “Fuchs had provided a detailed description of the plutonium bomb in June 1945,” Kurchatov’s deputy, Iulii Khariton, “and his colleagues had to check everything for themselves, since they could not be sure that Fuchs’s description was completely reliable.” The experimental reactor started working in December 1946, almost exactly four years after Fermi’s first “pile” in Chicago. Meanwhile preparations were started for a reactor to produce plutonium. The building that contained the reactor was erected—again by prisoners—on a site near Cheliabinsk. This reactor started working in June 1948, and began producing plutonium. A radiochemical facility was also ready to extract the plutonium from the exposed uranium.

Kurchatov knew from the information secretly passed on from Los Alamos that the spontaneous fission rate of plutonium was high, and that the plutonium bomb therefore needed the implosion method to set it off—i.e., a core of plutonium had to be surrounded “with high explosives so as to produce a shock wave that would travel inwards and compress the plutonium,” which would then immediately start to expand again. Kurchatov’s team was able to design the delicate “explosive lenses,” which made the detonation waves converge into the plutonium core. Finally the first Soviet atom bomb was tested on August 29, 1949, at a site near Semipalatinsk, with Beria present. It produced an energy equivalent to twenty kilotons of TNT, i.e., the same order of magnitude as the bombs on Hiroshima and Nagasaki.


This was four years after the start of the USSR’s crash program, about the same time taken from the start of the Manhattan Project to the first test at Alamogordo. Of course the scientists in charge of the Soviet project had the advantage of knowing that the bomb would work, and they benefited from both secret and public information, such as the Smyth Report, in deciding what choices to make among the different possibilities. But this was in a country devastated by the war, with many shortages and with a much smaller industrial base than the United States. It was an impressive achievement.

After the first test, work continued, more bombs were produced, and their quality improved. But there was a new challenge: to create a thermonuclear weapon or “hydrogen bomb.” Kurchatov started work on this as soon as the first fission bomb had been tested. He now had no help from intelligence reports in working out the design. Fuchs had attended one meeting on the hydrogen bomb before leaving Los Alamos, and had reported on this. But Holloway’s research shows that the ideas put forward at this meeting turned out to be misleading, and he finds no evidence of later leaks on the hydrogen bomb. In any case the Soviet design was based on a different principle from the American.

To start with, a theoretical group under Iakov Zel’dovich worked out a design for a hydrogen bomb. Kurchatov asked Igor Tamm, one of the most respected Soviet theoreticians, to check the group’s calculation. Tamm worked on this with the help of some of his students, including Andrei Sakharov and Vitalii Ginzburg. The group concluded that the design would not work.

But then Sakharov came up with a new proposal, which was improved by an idea of Ginzburg’s. As a result both Tamm’s group and that of Zel’dovich worked on the new design. This was tested in August 1953 at the test site near Semipalatinsk. It was expected that this test might cause radioactive fallout over a wide area, and at the last minute a large number of people were evacuated from the neighborhood. The yield of this test was the equivalent of 400 kilotons of TNT.

Further work by the theoretical groups led to a new modification with features similar to the American design conceived by Stanislaw Ulam and Edward Teller. Much complex calculation was needed to work out the details and this was helped by a powerful Soviet computer that had been developed about that time. Again there were problems in obtaining the needed materials. The design required lithium deuteride, a compound of lithium, in the form of the isotope lithium-6 with deuterium (heavy hydrogen). A complex process was needed to extract the rare isotope of mass 6 from natural lithium, while a large supply of heavy water was required to extract heavy hydrogen. Finally the bomb was ready for testing in November 1955. It produced a yield of 1.6 megatons, almost a hundred times that of the Hiroshima bomb. This was another remarkable achievement. Neither would have been possible without the hard and devoted work of the scientists and engineers. By no means all of them had affection for Stalin’s regime, but they felt that the country needed nuclear weapons to restore the balance with the West, in particular with the United States. In an article published in 1988 Sakharov wrote,

We (and here I must speak not only in my own behalf, for in such cases moral principles are formulated in a collective psychological way) believed that our work was absolutely necessary as a means of achieving a balance in the world.


Holloway does much to clarify Stalin’s attitude toward the atom bomb. After 1945 he claimed that it was not militarily decisive, and that it could not win a war. Nevertheless he felt it was important for the Soviet Union to acquire nuclear weapons as soon as possible. In 1945, Holloway writes,

Stalin did not believe that war was likely in the short term; nor…did he believe that Soviet divisions had lost their value. The immediate threat he saw was not military, but the threat of atomic diplomacy. He was afraid, as he had explained to Gromyko,…that the United States would try to use its atomic monopoly to impose a postwar settlement.

For the same reason, Holloway believes, Stalin wanted to have the means of delivery of such weapons to attack the United States, and he gave high priority to long-range aircraft and missiles.

The Soviet program, according to Holloway, was conceived for defense against an attack from the West. Western policy was for its part largely based on the danger of a Soviet invasion of Western Europe, but in all the Soviet documents seen by Holloway, there is not a single reference to plans for an unprovoked invasion. In the Western literature there are many discussions of the possibility of invading Eastern Europe or the Soviet Union, though this of course never became policy.

Stalin accepted Lenin’s thesis that there would be clashes between capitalist countries which would involve the Soviet Union, although socialism would be victorious in the end.

Stalin drew a direct analogy between the interwar years and the postwar period when he told T. V. Soong in July 1945 that Germany had recovered within fifteen to twenty years of the Treaty of Versailles; Germany and Japan, he said, would rise again. In his February 1946 speech he said that it would take at least three fiveyear plans to prepare for “all contingencies.” All of this suggests that he anticipated a new world war after an interval similar to that between the two world wars. Moreover, a new world war would originate, in Stalin’s conception, in the rivalry between the imperialist powers, including Germany and Japan, which would by that time have risen from defeat. He did not foresee the hegemonic position that the United States would come to occupy in the capitalist world.

But Stalin did not expect war in the short term. This is clear from his policies of industrial conversion and demobilization, which began in May and June 1945 and continued steadily during 1946 and 1947.

When the United States suggested international control of atomic energy, Stalin strongly suspected that this was a way of ensuring a permanent American monopoly of nuclear weapons. Even if the Baruch plan had not included a control commission whose members would not have veto powers, which was clearly unacceptable to the USSR, it still would not have been acceptable to Stalin.

Toward the end of his life, he became suspicious of everybody and he suspected his doctors of trying to kill him. In November 1952,

Stalin ordered the arrest of the leading Kremlin doctors, including his own physician, Vinogradov. Confessions were soon obtained by torture, and Stalin passed these around the leadership, saying “You are like blind kittens; what will happen without me? The country will perish because you do not know how to recognize enemies.”

Since most of the doctors were Jewish, the always endemic anti-Semitism in the USSR became much worse; but Jewish physicists, who were needed for the work on the atomic bomb, were spared. Lev Landau wryly remarked that this was the first time the atom bomb had proved a defensive weapon. But Stalin and Beria never lost their suspicion of scientists. If the tests had failed, they had ready a list of scientific leaders of the atom-bomb projects who were to be arrested. When the tests succeeded, Kurchatov and his colleagues were showered with honors. During the postwar years there was a new attempt by Marxist philosophers to attack modern physics, as they had during the 1930s, but in view of the importance of the physicists for the atomic-weapons work, this was suppressed.

After Stalin’s death in March 1953 the tense atmosphere somewhat eased. The arrested doctors were released. Beria, against whom resentment had been mounting, and who had now lost his protector, was arrested and accused of being “an agent of international imperialism and an enemy of the Soviet people”—charges he himself had often made against innocent people. After a secret trail he was executed in December 1953.

Foreign policy became more conciliatory. The Soviet Union cooperated with the 1955 Geneva conference at which Eisenhower put forward his proposals—called “Atoms for Peace”—to set up the International Atomic Energy Agency, which would receive and administer contributions of fissionable material from governments for peaceful purposes. This had no connection with atomic weapons but led to cooperation both on atomic power and on ways to produce power from thermonuclear reactions, which up to that time had been highly secret on both sides. Above all it opened the way for personal contacts between scientists. I remember a young Soviet physicist saying to an American, “We are so glad we have been told to be nice and friendly to you.” Kurchatov took an active part in such international contacts, and arranged to give a lecture in England about thermonuclear power. From then on, cooperation in peaceful science has continued, to mutual benefit. Holloway arrives at the following view of the community of the Soviet physicists, or at least part of it:

The scientific community—and especially the physics community—was, for all its failings, the closest thing to civil society in the Stalinist regime. The scientist—or at least scientists like Frenkel’, Kapitsa, Tamm, Vernadskii, and later Sakharov—was the nearest approximation to a citizen that could be found in Soviet society. The scientist as citizen was a figure of great significance for the society as a whole. In providing protection for Soviet physics, the bomb had done something more: it had helped to protect a small element of civil society in a state that strove for totalitarian control over the life of society.

About half of Holloway’s book is devoted to the history of nuclear-weapons projects in the Soviet Union, the other half to an account of Stalin’s foreign policy in the light of nuclear developments. He has devoted many years to collecting information, and he has made several visits to the Soviet Union. In the beginning the subject was surrounded by great secrecy, and it is surprising how much information he found and how many Soviet scientists and officials were willing to talk to him. But of course the real flood of information came only in the last few years following the collapse of the Soviet Union. Holloway must have been very busy reading formerly secret documents and selecting what to quote. His book is particularly impressive in backing up almost every statement, particularly on the history of the projects, with official records or with statements of the participants. Perhaps in some cases he quotes more opinions than are needed. In the chapters about foreign policy, the sources in some cases can only speculate about Stalin’s intentions; and Holloway has to present several interpretations of Stalin’s actions or his words. His account of foreign policy is very general, and not restricted to situations which are directly linked to nuclear weapons.

If I have a minor complaint it is that in the interests of a logical presentation, simultaneous developments are sometimes separated. For example, Holloway mentions the Soviet work on long-range jet bombers and missiles, but it is not clear whether the problem of delivery across the Atlantic was actually solved by the time Stalin and others talked about having the capacity to drop nuclear weapons on the US. The discussion of how Soviet foreign policy became less rigid after Stalin’s death is separated from the account of the “Atoms for Peace” conference, so there is no discussion of whether one influenced the other.

Another, very slight, complaint, should probably be directed at the publisher, not the author: in many places sources are quoted in paragraphs starting without indentation. It is not clear whether this is meant to indicate verbatim quotation, and if so, whether the quotation continues into the next paragraph. But these are very small points about a perceptive, highly informative, and altogether excellent book.

This Issue

February 16, 1995