( Oxford University Press, 2005)
Having praised the glory of Soviet H-bomb physicists, it's time to ask how such a one-sided picture of Soviet thermonuclear success can be painted in the era of glasnost? Were these achievements really independent?
Indeed, both the vigor of the Soviet intelligence agents in the American atomic project and the enormous volume of spy information about the American A-bomb -- thousands of pages -- are now commonly accepted. In 1996 five veteran Soviet agents were given the title of Hero of Russia for their efforts that made possible "the liquidation of the US nuclear weapons monopoly in the shortest possible time." 
Some people feel that these belated heroes' stars dimmed the Stars of the Heroes of Socialist Labor awarded to the physicists forty years ago. Didn't the stream of intelligence information about American nuclear arms yield anything of substance about the thermonuclear bomb? In 1997 American journalists introduced Theodore Hall, a former Soviet agent nicknamed Mlad, to the world.  He had worked in Los Alamos in the mid-1940s and he worked for both countries. His biographers wrote that besides passing on information about the A-bomb in October 1947, he informed Soviet intelligence that Americans were using lithium in their work on the super-bomb: "The Soviets were quick to seize the importance of the idea and perfect it on their own. In December of the following year, Soviet physicist Vitaly Ginzburg proposed the use of lithium-6 deuteride as a source of tritium in a Soviet H-bomb."  Here the American journalists referred to German Goncharov, the same Russian veteran physicist from Arzamas-16 whose publications are also a key sources for this book.
There were other agents who have not been exposed yet -- a certain Anta, someone named Aden, and an indeterminate number of others. So, some American thermonuclear veterans think that the second Soviet H-bomb (1955) was made with American help. The first bomb, Sloyka, did not arouse doubts simply because no American analog had been built. But it was the second bomb that embodied the basic principle of thermonuclear weaponry. Confronted with the puzzle -- how could their 4-year lead on the A-bomb have been reduced to a year and a half on the "real" H-bomb -- the Americans saw the answer in the incident that occurred on January 7, 1953.
On that day John Wheeler, a prominent participant in the American thermonuclear project, was going to Washington by train carrying a secret document with important information about the thermonuclear bomb. He had to take it with him when he went to toilet; but he forgot it there on his way out. When he remembered and returned for it, the document was gone. Wheeler immediately informed higher levels of authority about the loss, but the most careful searches yielded nothing. The situation was aggravated by the fact that the train was filled with leftist demonstrators traveling to the White House to demand mercy for Ethel and Julius Rosenberg, who were awaiting execution. It's entirely possible, as the then chairman of the US Atomic Energy Commission, Lewis Strauss, thought, that there were foreign agents among the passengers who knew the nature of Wheeler's work and were following him. 
Where could this missing document have gone? For a long time the answer seemed almost obvious -- into Beria's hands. This was the view of many American thermonuclear veterans. In particular, this was the understanding of Tom Reed, who, in the 1950s-60s worked at the Livermore Laboratory, then was Air Force Secretary and Presidential Special Assistant. 
However, archival evidence recently made available virtually rules out that the Soviet agent had gotten such a valuable catch. Moreover, it rules it out from both the American and Russian sides. It has become clear from the American side that whereas Wheeler was carrying two documents in a manila envelope, only one document disappeared from the envelope in the train toilet.  It's difficult to imagine such a modest spy, satisfied with only a part of an available trophy. It's easier to imagine a person peeking into a stranger's envelope out of curiosity and seeing the terrifying classification "Top Secret." He probably would have been stung by the realization that the fingerprints he left on this damned paper would lead him to the same electric chair that awaited the Rosenbergs, and felt he had to destroy the paper at once.
But more importantly, there is no place in Russian thermonuclear history for the supposition that the document that vanished in January 1953 wound up in the USSR. Indeed, there's no mention of the key ("Third") idea yet in the Zeldovich-Sakharov report about the A-D-S diagram that came out a year later in January 1954. And why was Beria's successor, Malyshev, so opposed to the development of this idea? And why was Kurchatov reprimanded?
Thus, the only "material" evidence of the Soviet's thermonuclear dependence melted away. There remain some questions about the role of intelligence: Why didn't atomic espionage go "hydrogen," and why did it drop off so drastically? The answer to both is that American counter-intelligence went into full swing right at that point. Klaus Fuchs was arrested in January 1950, then a few months later, the Rosenbergs. Those who remained kept a low profile. Besides, the motives of the Soviet agents of that time were primarily ideological. These motives abruptly weakened after the 1949 Soviet A-bomb test -- after the balance of power was reinstated.
But if there really wasn't any thermonuclear espionage, how was it possible that it took the Americans three years (1951-1954) to implement their "third idea," while their Soviet colleagues only needed a year and a half?
To speak of the role espionage played here, we should distinguish between three stages of the Soviet nuclear project: the 1949 A-bomb, the first thermonuclear bomb of 1953 (Sloyka), and the full-fledged thermonuclear bomb of 1955.
That thousands of pages of American secret reports wound up at the disposal of Kurchatov, the director of the Soviet atomic project, is firmly established fact. That the first Soviet A-bomb, detonated in 1949, was a copy of the American plutonium bomb ("Fat Man") tested near Los Alamos and dropped on Nagasaki, has also been confirmed.
At first glance, it seems impossible to reconcile these facts with the assessment made by Lev Artsimovich (one of Kurchatov's deputies) that espionage saved the Soviet Union a year or two in making the A-bomb. Although Western historians and the Encyclopedia Britannica agree with this assessment, the physicist Artsimovich can be too easily suspected of being biased in favor of the physicist's contribution .
But Hans Bethe, who wrote in a 1946 article published in the US that "any one of several determined foreign nations [including Russia] could duplicate our work [to develop an A-bomb] in a period of about five years" is harder to mistrust.  This physicist not only received a Nobel Prize for the theory of thermonuclear energy of the stars, he directed all the theoretical work in quite a practical manner at Los Alamos. That is why Bethe knew very well exactly what scientific research was necessary to develop the A-bomb. He knew that this research did not require genius, just enough high-level physicists. And he was also familiar with the caliber of Soviet physicists.
Soviet physicists had had to do all the required calculations and experiments themselves. After all -- they answered for the results with their own heads. That was why many veterans of the Soviet projects initially so distrusted the information about how much espionage had contributed -- they were the ones who had measured and calculated everything. Kurchatov, who knew the American results, helped them avoid some of the blind alleys, which is what shortened the path by one-fifth, if one trusts Bethe's evaluation.
Does saving a year or two for the Soviet A-bomb merit the title of Hero of Russia given to the espionage agents? It probably does if an atomic attack on Russia would have occurred otherwise in that year or two.
The seeming disparity between thousands of pages of espionage materials and a savings of only 20 percent isn't the only paradox in the history of atomic espionage. The biographers of Hall/Mlad did an excellent journalistic investigation and gave us an opportunity to learn about the motives of people who betrayed the most precious Western secrets to the West's chief enemy. These people had, of their own free will, served what they thought was socialism, when, in fact, it was Stalinism. And they served unselfishly, if one considers the satisfaction of personal heartfelt aspirations unselfish.
The American journalists who told Hall's story lacked knowledge of the history of physics and Soviet history to adequately fit his contribution to the history of the Soviet atomic project. The paradoxical conclusion one must reach from Hall's biography is that in passing on these most valuable secrets, Hall actually hindered the Soviet atomic project instead of helping it.
Amazing as it seems, Beria suspected "disinformation" in the espionage dispatches and considered "that the enemy is attempting to lure us into expending enormous resources and efforts on work which has no future promise," even after Hiroshima, when there was no doubt that the A-bomb was feasible. 
How could that be? After all, Beria had on his desk three independent espionage reports from the very center of the American atomic project. Hall was unaware that right there at his side was Klaus Fuchs, another Soviet agent, older and higher placed, who passed on more complete and accurate information about the A-bomb to Soviet intelligence. There was a third active agent -- Sergeant David Greenglass.
Beria was anything but stupid. Two of his predecessors as Chief Stalin's Gendarme wound up in the meat grinder they themselves had operated. But Beria, after seven years of service, became a marshal and successfully directed the Atomic Project for the following seven years. This took more than mere cunning and wariness.
As the chief of intelligence he could distrust his own agents, considering their successes too good to be true. And really, as Hall's biographers write, "This was a rare phenomenon, unique in American history: Three individuals, unknown to one another, decided for reasons of political philosophy to commit espionage at the same time, in the same place, giving approximately the same kind of information to the same foreign government." 
The most valuable and reliable of the three agents was Fuchs, a mature, balanced 33-year-old who held a high-level scientific position and had been an active anti-fascist in Germany. And the most suspicious character was the 19-year-old Hall, the son of a furrier who showed up on the doorstep of the New York Soviet intelligence office. This volunteer's youth and his petty bourgeois background -- unfavorable by Soviet standards -- aroused the fear that he was a tool of disinformation.
Unlike his comrades in the Politburo, Beria seemed free of pro-socialist sentiments. And it was more difficult for him to believe that so many Americans were willing to risk their lives all at once for the sake of the socialist nation than to suppose that American secret services were trying to deceive him, and in a rather crude way. Consequently, not only did Mlad arouse his suspicions, so did Fuchs, since the content of their information coincided.
But if Hall did not help the Soviet A-bomb, then perhaps he did something at the next stage of developing a super-weapon? He himself denies that he made any contribution to the Soviet H-bomb. Even if he did report that the Americans were thinking about using lithium in the super-bomb, that doesn't constitute help.
As Goncharov discovered in the Russian archives, Soviet intelligence learned in 1947 that lithium was involved in American research. But the physicist Goncharov emphasized that intelligence did not report anything about the isotopic composition of lithium. Hall's biographers paid little attention to such "minor details" -- the main thing was the word "lithium." And for greater effect, the journalists called lithium, along with hydrogen, helium, and beryllium, "the four mysterious light elements." But they didn't explain what was mysterious about them -- they really are the lightest elements, but they had been discovered a long time ago.
Thermonuclear explosive is made not just from lithium, but from its rare isotope lithium-6, combined with deuterium (LiDochka). This substance was used for the first time in Sloyka.
Hall's biographers apparently did not know that lithium is the first solid substance among the light elements, and thus easier to deal with than deuterium and tritium, which are gases. Lithium was used in the very first nuclear reaction made by a particle accelerator in 1932. And the biographers most certainly didn't know that Ginzburg, the future father of LiDochka, talked about this reaction in his popular 1946 pamphlet The Atomic Nucleus and its Energy. He illustrated nuclear energy's reserves "using lithium as the example" (rather than commonplace uranium): "You could use 100-200 grams of lithium instead of an entire train load of coal." 
That is why when Ginzburg was included in the work on the hydrogen bomb two years later, he was just the person to start with lithium. Just going from simple lithium to the specific mechanism of utilizing LiDochka was already a true achievement, which Ginzburg reached in November 1948. Teller arrived at it a year and a half later in the USA. 
But even without this chronology, it's difficult to imagine that if Beria had in his hands information related to the construction of the super-bomb, he would have given it to the just recently formed auxiliary FIAN group and not to Zeldovich, the group which had been working inside the project from the start. Let's remember that Beria allowed even purely scientific data to be given to Tamm only after Khariton's intercession.
 A. Poleshchuk, "Sluzhba vneshnei razvedki Rossii ne imeet konkurentov v mire [Russia's Foreign Intelligence Agency Has No Competition in the World]" in Nezavisimaia gazeta, December 18, 1996.
 J. Albright, and M. Kunstel, Bombshell: The Secret Story of America's Unknown Atomic Spy Conspiracy (Random House, 1997).
 Ibid., p. 186-187.
 L. L. Strauss, Men and Decisions. (Garden
City, NY: Doubleday, 1962), p. 270.
R. Pfau, No Sacrifice Too Great: The Life of Lewis L. Strauss (Charlottesvile: The University Press of Virginia, 1984), p.137.
Jack M. Holl. "Notice to Newsmen." December 28, 1975 (Washington Post, December 29, 1975).
John A. Wheeler. Oral history interview conducted by Finn Aaserud, May 23, 1988, p. 81-82. American Institute of Physics. Center for the History of Physics.
John A. Wheeler with K. Ford. Geons, Black Holes, and Quantum Foam: A Life in Physics (New York: Norton, 1998), pp. 284-286.
 Thomas C. Reed is the author of a book about nuclear close calls during the years 1953-1992, At the Abyss: An Insider's History of the Cold War, Ballantine Books, 2004.
 Gregg Herken. Brotherhood of the Bomb: The Tangled Lives and Loyalties of Robert Oppenheimer, Ernest Lawrence, and Edward Teller. Henry Holt, New York, 2002, p. 259-260, and Tom Reed, personal communication.
 Hans Bethe and F. Seitz. "How Close is the Danger?" in One World or None. Edited by Dexter Masters and Katharine Way. (New York, 1946; London: Latimer House, 1947), p.100.
 A. A. Yatskov, "Atom i razvedka" [The Atom and Intelligence Services] in VIET (1992), No. 3, p. 105.
 J. Albright and M. Kunstel, Bombshell, (1997), p. 156.
 V. L. Ginzburg, Atomnoye iadro i ego energiia [The Atomic Nuclear and Its Energy]. (Moscow: OGIZ [Association of State Publishing Houses (1930-1949)], 1946), p.51.
 "Policy and Progress in the H-Bomb Program: A Chronology of Leading Events," Joint Committee on Atomic Energy, Jan. 1, 1953, p. 79. Chuck Hansen. The swords of Armageddon: U.S. nuclear weapons development since 1945. Sunnyvale, CA: Chukelea Publications, 1995, Vol.3, p. 137.