“From Russia with Love”. The Понтеко́рво Affaire
Stefano Salvia∗
On August 31, 1950, in the middle of a holiday in Italy, the physicist Bruno
Pontecorvo abruptly left Rome for Stockholm with his wife and his three sons, apparently
without leaving any trace. He was expected to come back to England in a few weeks, since he
was appointed to the chair of experimental physics at the University of Liverpool, which was
due to take up in January, 1951. Hypotheses and suspects frantically followed one to another
in the next months: kidnapped by the Soviets because of his work on the Anglo-Canadian
atomic project? A deliberate defection to the USSR? Anyway, no doubt that he was on the
other side of the Iron Curtain.
Pontecorvo was the youngest member of the “Via Panisperna boys”, the research
group on atomic physics led by Enrico Fermi in Rome from 1929 to 1938. In 1934 he
contributed to Fermi’s famous experiment showing the properties of slow neutrons, which led
to the discovery of nuclear fission. As he would tell in several interviews after 1990,
Pontecorvo felt increasingly oppressed by the fascist regime and scared about the idea of an
alliance between Italy and Nazi Germany.
Bruno Pontecorvo (1913-1993)
∗
Ph.D. in History of Science, University of Pisa (e-mail: stefano.salvia@tiscali.it).
1
From left to right: Ettore Majorana, Emilio Segrè, Edoardo Amaldi,
Franco Rasetti, Enrico Fermi. Foto by Bruno Pontecorvo
In 1936 Pontecorvo moved to Paris to work with Irène and Frédéric Joliot-Curie on the
effects of collisions between neutrons and protons through the study of radioactive isotopes
and isomers. During this period, his leftist ideas turned into an open adhesion to communism,
also because of Joliot-Curie’s influential personality as socialist physicist. In 1938 he knew
Marianne Nordblom, a young communist student, who would become his wife. Being of
Jewish origins, Pontecorvo was unable to come back to Italy because of the “racial laws”,
approved in the same year. In 1939 he met Luigi Longo and many other political refugees,
joining the clandestine Italian Communist Party (PCI). He remained in Paris until 1940, when
the Nazi occupation forced him to move to Spain and shortly after to the United States.
At that time America was still a neutral country with the largest Italian community
living outside Italy, while Great Britain was facing the threat of a German invasion and
dealing with the problem of “enemy foreigners” on its territories. For an Italian refugee it was
definitely easier to establish in the US. Furthermore, the British intelligence service had
already opened a file on Bruno Pontecorvo. This early report of the MI5 regarded Pontecorvo
as «moderately unwelcome», because he belonged to Joliot-Curie’s entourage.
Thanks to Emilio Segrè, who had moved to Berkeley in 1938, Pontecorvo was
recommended to Serge Alexander Scherbatskoy and Jacob Neufeld at the Well Survey
Incorporated in Tulsa (Oklahoma), a pioneer company engaged in the application of nuclear
physics and geophysics to mineral prospection and well-logging. Since the very beginning of
2
his scientific career, Pontecorvo was interested in the interactions between nucleons and
atomic/molecular structures. The idea of studying the absorption and scattering of slow
neutrons to detect the physico-chemical properties of the different geological layers of an oil
well came directly from his previous work in Rome and Paris. The combination of electron,
gamma-ray, and neutron well-logging could provide a much more accurate prospection, also
for deposits of radium and uranium1.
Pontecorvo worked at the WSI for two years, before shifting his attention from the
geophysical applications of radioactive sources to the sources themselves and their detection,
visiting different laboratories of the East Coast and meeting Fermi in Chicago. Despite his
close friendship with Fermi, Pontecorvo was not called upon to take part to the Manhattan
Project, probably because of his committed socialist beliefs. On September 25, 1942,
Pontecorvo’s house in Tulsa was accurately inspected by two FBI agents, since Pontecorvo
had become “enemy foreigner” even in the US and he was working on strategic subjects.
During the inspection they found Marxist literature and pro-communist leaflets, which were
the origin of a second, much more important file on the Italian physicist. This American
“Pontecorvo dossier” is still classified and all we know about comes from the declassified
documents of the British intelligence.
In 1942 Fermi and Pontecorvo had several occasions to confront their data on the
propagation of neutrons across different materials, but Fermi never told him why he was so
interested in the subject. We do not know if the FBI itself prevented Fermi from involving
Pontecorvo in the American atomic programme, but Fermi must be informed of their recent
visit to his friend’s house and he was very cautious about diplomatic issues. However, in 1943
Pontecorvo was invited to join the Montreal and Chalk River Laboratories in Canada, where
he concentrated on prospection of strategic minerals, design of nuclear reactors moderated by
heavy water, and safety issues related to anti-radiation shields. He was also interested in
theoretical particle physics, cosmic rays, neutrinos, and the decay of muons.
Pontecorvo was thoroughly examined during a preliminary interview by the security
board responsible for Tube Alloys, the nickname of the Anglo-Canadian atomic project, but
nothing really suspicious was found. On the contrary, he seemed to be the right person in the
right place. His leftist views were even a guarantee of active collaboration against Nazifascism, without considering that the Soviet Union was still an allied country at that time.
1
Bonolis, Luisa: Bruno Pontecorvo, from slow neutrons to oscillating neutrinos, in: American Journal of
Physics, 73 (2005), S. 487-499.
3
When in 1945 Igor Gouzenko, a former employee at the Soviet embassy in Ottawa,
confessed to the Canadian authorities that he was part of an international espionage network
made of NKVD officers and Western scientists which had infiltrated Tube Alloys, it came out
very soon that the atom spies were not “enemy foreigners” but British and French physicists,
like in the famous case of Alan Nunn May, arrested in 1946. Nunn May’s claim that helping
the USSR to develop its own nuclear programme was vital to defeat Germany, as later Robert
Oppenheimer’s concern that only the end of the Anglo-American monopoly on nuclear
technology would ensure world peace through atomic deterrence, was not necessarily
connected with communist beliefs and pro-Soviet feelings.
This would become less and less obvious after 1945. One usually says that Hiroshima
and Nagasaki were at the same time the last act of WWII and the first act of the Cold War.
The collective hysteria of the “Red Scare” in McCarthy’s era was functional to Henry
Truman’s containment policy against the USSR and its new allies: the communist block
would be able to overcome the military and political supremacy of the “free” world only by
means of its spies and collaborators disseminated in the West.
The hunt for the “fellow travellers” did not affect Pontecorvo yet, because of his
fundamental contribution to Tube Alloys, but he felt more and more upset by the security
restrictions imposed by James Chadwick to all the physicists working in the programme, after
the Gouzenko and the Nunn May affaires. In 1948 he obtained the British citizenship (maybe
helped by Fermi) and was invited by John Cockcroft to join the Nuclear Physics Division in
Harwell to contribute to the British atomic bomb project at the AERE secret laboratories.
As far as we know from documents declassified in the 1990s, Scotland Yard and the
MI5 had been informed in the meanwhile by their FBI counterparts that Pontecorvo was a
member of the PCI before 1940, even if he did not seem to be actively involved in communist
propaganda. Despite his socialist commitment, Pontecorvo seemed to be trustworthy enough
to work for the Royal Army, even if he was constantly surveyed by the secret services, as
many other nuclear physicists in Great Britain at that time. The information evidently came
from the FBI dossier opened in 1942, enriched with new details about the pro-communist
activities of other members of the Pontecorvo family who lived in Italy, like Bruno’s
youngest brother Gillo and his cousin Emilio Sereni. Both were former communist partisans
during the Nazi occupation and had a prominent role in the post-war PCI.
Pontecorvo’s position was becoming very difficult in an age of anxiety, suspicion, and
paranoia, especially after another famous case of atomic espionage, that of Klaus Fuchs.
Differently from Nunn May, Fuchs was precisely the kind of “enemy foreigner” the allied
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military services were so afraid of during the first years of WWII. Moreover, there was no
doubt that his spying activity, begun in 1942 when he joined the Manhattan Project, was due
to a strong and aware commitment with the Soviet system, dating back to his youth as KPD
militant in the late Weimar Republic. From this point of view, Fuchs was the first atom spy of
the Cold War who deliberately acted as such, being recruited in Chicago as formal
collaborator of the NKVD. The Fuchs affaire was the casus belli of an underground war
between officially allied intelligence services, which was also an invisible war between the
two founders of the NATO, with their divergent political visions2.
Great Britain had developed a much more pragmatic attitude towards the Soviets,
because of its geopolitical closeness to Europe, while the Americans blamed this
accommodating policy as inadequate to ensure security in the new world scenario.
Furthermore, the British claim for strategic independence from the USA was regarded by the
American administration as a sign of unreliability, when unity, loyalty, and transparency were
indispensable to fight against the “Red Threat”. The high permeability of Tube Alloys to the
Soviet espionage was a serious failure for the British intelligence and might turn out as a great
scandal. Security controls and investigations must be stricter, following the example of
Herbert Hoover’s anti-communist campaign as executive director of the FBI. Scotland Yard
could not risk a Pontecorvo case, after that of Klaus Fuchs. What was just suspicious, before
1950, was now sufficient to prevent a nuclear physicist from working on secret projects.
Pontecorvo was removed from all his duties in Harwell, his access to classified files
denied. Cockcroft wanted to avoid any publicity to the whole thing, so he strongly
recommended Pontecorvo for the chair of experimental physics in Liverpool, which was to
become a high-rank research center for theoretical and particle physics, but with no direct link
to the British atomic programme. Pontecorvo was appointed ordinary professor in Liverpool
in July 1950, even if with the opposition of some members of the academic evaluation panel,
who would prefer a British physicist and did not understand Cockcroft’s personal interest in
his nomination. He would be free to work at his best topics, i.e. neutrinos, mesons produced
by colliding nucleons, cosmic rays, and particle astrophysics, with no secrecy issues.
However, Pontecorvo was very unhappy with this solution, which sounded more like a
confinement after an arbitrary condemnation. It was clear to him that Liverpool would be a
hostile environment for a Jewish-Italian scientist suspected of being a communist spy.
Moreover, in 1948 he had joined the collective legal action carried on since 1946 by Fermi,
2
Williams, Robert. C.: Klaus Fuchs: Atom Spy, Cambridge (MA) 1987; Friedmann, Ronald: Klaus Fuchs: der
Mann, der kein Spion war. Das Leben des Kommunisten und Wissenschaftlers Klaus Fuchs, Rostock 2006.
5
Amaldi, Segrè, and Rasetti against the American Government to claim for their rights and for
adequate royalties upon any nuclear technology patented in the US which was based on the
properties of slow neutrons.
A former refugee and “communist traitor” who was openly challenging the US
administration, accused of having tricked the Italian physicists exploiting their work for free
because of the urgent needs of the war: another good reason for the British and American
intelligence to put him under surveillance. The action would only come to an end in 1951,
with a refund of almost 300.000 $: far less than the sum originally asked by the “Via
Panisperna boys”. In the meantime, it assumed the meaning of a scientific, economic, and
diplomatic controversy between Italy and United States.
On July 24, 1950, Pontecorvo wrote to James Mountford, rector of the University of
Liverpool, that he would travel across Italy to visit his relatives and friends. His sudden flight
to Stockholm on August 31 could be explained as an unforeseen stay in his wife’s hometown,
right before coming back to the UK. The day after, however, the Pontecorvos moved to
Helsinki and then vanished. Their abrupt disappearance soon became an international affaire
in a period of increasing tensions between the two blocks, causing much concern to the
British and American intelligence, who was worried about the escape of atomic secrets to the
Soviet Union. Initial rumours about Pontecorvo being kidnapped by the KGB quickly turned
into the suspicion that he had deliberately crossed the Finnish-Russian border, helped by
Soviet agents. Facing the possibility that Pontecorvo was really a communist spy defected to
the Soviet Union, maybe bringing classified material along, the British authorities
immediately pointed out that he had had very limited access to secret subjects. Even later no
official allegation of transferring military secrets to the Soviets was made against him3.
By the way, there are two different versions of his travel, which are still controversial:
1) he moved from Stockholm to Helsinki by plane and from Helsinki to Leningrad by train,
after a short transfer from the airport to a Russian base in Finland on a Soviet diplomatic car;
2) he went directly from Stockholm to Leningrad on the boat Belostrov. The circumstances of
his hasty departure are obscure because Pontecorvo never wanted to tell them in detail. We
know from the registers of the bureau of Scandinavian Airlines in Rome that he paid 602 $ for
the tickets: by cash and with six banknotes of 100 $. At that time, they were not available at
any bank, only at embassies and consulates.
3
Turchetti, Simone: Il caso Pontecorvo. Fisica nucleare, politica e servizi di sicurezza nella guerra fredda,
Mailand 2007.
6
Combining this information with that coming from the secret archives of the former
PCI, now accessible to historians, we are able to provide a plausible reconstruction of those
events. Pontecorvo’s cousin, senator Emilio Sereni, was a very important figure of the PCI
under Palmiro Togliatti’s secretaryship, before the “de-Stalinization” of the Party after 1953.
Today we know that he was one of the members of a secret security commission, headed by
Togliatti himself and unknown to the rest of the Central Committee. They coordinated the
activities of a clandestine network, known in Italy as “Red Gladio” and directly connected
with the KGB. This paramilitary structure had already helped many Italian communists to
emigrate to the East, providing false passports and safe passages through the Iron Curtain. It
must be ready to take over the Central Committee, if the survival of the Party was in danger4.
Pontecorvo’s hurry leads to the conclusion that his defection was not prepared from
long time, but decided just a few weeks before. Since he met his cousin during a brief stay on
the Dolomites, before going to Rome, he probably discussed with him the possibility of
becoming a Soviet citizen. Pontecorvo and his family were also close to the “Partisans of
Peace”, a pacifist organization which was quite similar to the Pugwash movement, but part of
the Comintern (Cominform) and led by Sereni himself. As already noticed by Albert Einstein
in his last years, the PoP were “pacifist” in a very particular sense: they strongly criticized the
Western nuclear policies, but they tended to justify the Soviet atomic programme as the
inevitable response to them.
Historians actually agree that Pontecorvo was helped by Emilio Sereni, who contacted
the Soviet embassy in Rome and organized the whole operation, providing him with the
money he needed. Probably he never mentioned the role played by Sereni to protect his
cousin, his own family, and the “Red Gladio” from a political scandal in Italy. In the USSR
Pontecorvo was welcomed with honour. He was given many privileges usually reserved only
to the Soviet nomenklatura and awarded the Stalin Prize in 1953, the membership of the
Soviet Academy of Sciences in 1958, and two Orders of Lenin.
However, he was isolated from the rest of the world for many decades, a part from one
official press conference on March 1, 1955, when he was authorized to appear in public and to
explain to Western journalists the reasons of his choice. According to him, he had moved to
Russia because he rejected capitalism and wanted to live in a socialist system. He would reach
such a decision after he left Canada, abhorring the idea of working for the sake of AngloAmerican imperialism. Having been one of Fuchs’s closest friends in Harwell, he did not
4
Caprara, Maurizio, 1997: “Lavoro riservato”. I cassetti segreti del PCI, Mailand 1997.
7
want to live as renegade in a paranoiac society obsessed by communist traitors. Of course we
must be very careful about statements like these, which might be somehow “suggested”.
Pontecorvo always denied of being a spy recruited by the KGB and informed about
Fuch’s activity, as well as he always maintained to work exclusively on high energy particles
and oscillating neutrinos, denying any direct involvement in the Soviet atomic programme.
This last statement seems to be another half-truth. If it is so, why did the Soviets confine him
and his family in a hotel room in Leningrad for several days, before transferring them to
Moscow and then to Dubna? Did they want to make sure about his reliability? They could
take a great propagandistic advantage from presenting him immediately as the great physicist
who had chosen to support the “right side” of the Cold War, comparing him to the “socialist
hero” Klaus Fuchs and to many other victims of anti-communism in the West.
Did Pontecorvo really work on non-strategic subjects in Dubna, where most of the
secret nuclear laboratories of the USSR were concentrated and where most of the German
specialists recruited by the Soviets had been employed right after the end of the war?5 If it is
the case, why did the Russians prevent him from having any contact with the outside world
for almost 30 years? Only in August 1978 he was allowed to leave the USSR and to come
back to Italy for two months to attend a symposium in Rome on the occasion of Amaldi’s 80th
birthday. Since then, he was relatively free to travel to the West, even if for short periods.
Pontecorvo in Moscow (1955)
5
Holloway, David: Stalin and the Bomb. The Soviet Union and Atomic Energy, 1939-1956, New Haven 1996.
8
We know that he was examined by a mixed commission of nuclear physicists and
officers of the Red Army at the Institute for Physical Problems in Moscow, before moving to
Dubna. Maybe he did not know anything new on atomic bombs, but his expertise in reactor
design and neutron logging applied to geological prospection must be very useful, since in a
few years the Soviets filled the techno-scientific gap both in the design of reactors moderated
with heavy water and in uranium prospection that still in 1950 divided them from the US.
Furthermore, we know from declassified documents of the British intelligence that
Pontecorvo was sighted in 1953-54 as member of a Soviet delegation at the western boarder
between USSR and China6. Did he contribute to the development of the Chinese nuclear
programme, before the end of the Soviet-Chinese cooperation in 1958?
The Pontecorvo affaire has been object of a harsh political debate in Italy, very close
to the Iron Curtain, where the strongest and the most “heterodox” communist party in the
West was excluded from any role in the national government since 1948 but always
maintained its cultural hegemony until 1990. Who was Bruno Pontecorvo, beyond his
unquestioned scientific achievements? A model of “socialist science” or a utopian scientist,
victim of a totalitarian delusion as many other intellectuals in the 20th century? A man of
science who always promoted peaceful applications of atomic energy and never wanted to
have anything to do with the military, like Franco Rasetti or Norbert Wiener? A communist
spy who contributed to pass strategic information to the East? A physicist who soon realized
that the Soviet atomic bomb was the only way to balance the nuclear power of the USA and to
preserve global stability, like Oppenheimer?
The perception of Pontecorvo’s case changed in the public opinion from 1950 to the
early 1990s, as a mirror of the local and global tensions of the Cold War. In Italy, it also
reflected the complicated history of the post-war PCI, from Stalinism to anti-Soviet eurocommunism, until the social-democratic turn of the late 1980s. The huge amount of primary
sources that such an inquiry would need range from newspaper articles to historical essays
and popular books, from interviews and personal records to TV documentaries and related
materials recently published on the Web. Pontecorvo’s autobiographical notes and statements,
starting from those concerning the evolution of his scientific, social, and political views as
Jewish-Italian-Soviet physicist, should be confronted with the “revelations” made in the mid1990s by some former agents of the KGB like Pavel Sudoplatov, which have renewed the
public interest for the 1950 affaire and re-opened the Pontecorvo dossier, so to speak.
6
Goodman, Micheal S.: Spying on the Nuclear Bear. Anglo-American Intelligence and the Soviet Bomb,
Stanford 2007.
9
According to their “indiscretions”, which are obscure and contradictory in many
points, Pontecorvo was not a formal agent, like Fuchs, but an informal collaborator of the
Soviet intelligence since 1940, after he joined the PCI. He would have passed crucial
information about the very early stages of the Manhattan Project during his short stay in the
USA, something that Fermi would be suspicious about but unable to prove. His secret activity
would continue in Montreal, spying on the Anglo-Canadian nuclear programme. As member
of the AERE project in Harwell, Pontecorvo would have access to top secret files which were
extremely useful for the Soviets. His decision to escape to the East would date back to the
conclusion of Fuch’s trial in 19507.
The “real” Pontecorvo finally revealed or just an attempt from former Russian
spymasters to sell the most (in)convenient truth to Western press, in order to gain money,
credit, and visibility after the collapse of the USSR? An important consequence of Gorbacëv’s
glasnost or rather the last version of Soviet disinformacija? Again, we deal with half-truths
and true lies: typical of this kind of people and of their epoch. On the one hand, historians of
science are very sceptical about the reliability of such “testimonies”, even if they are
important sources for cultural history on their own. On the other hand, we should be cautious
with reconstructions biased by some apologetic attitude towards contemporary scientists.
The same might be said for Pontecorvo’s late reflections upon his political
commitment. He defended dissident colleagues like Andreij Sacharov and admired Gorbacëv
as reforming leader, but he was definitely disillusioned about the Soviet system. This does not
imply that he abandoned socialism for capitalism: like in the case of Lev Landau, his
frustration came rather from having realized that the USSR was all but a socialist country.
This was probably the “error” he referred to, talking about his decision to live in Russia8.
Anyway, as former Soviet citizen, Pontecorvo was the strongest opponent of early
NATO attempts to exploit strategic human and techno-scientific resources by means of a
mass immigration of Russian specialists to the West, immediately after the dissolution of
USSR and the political chaos that followed. On the contrary, he supported Carlo Rubbia’s
international effort to save the ex-Soviet academic institutions and research laboratories with
a sort of “Marshall Plan” built by the world scientific community. As a matter of fact, the
Pontecorvo affaire is still far from being solved ... as many other secrets of the Cold War.
7
Sudoplatov, Pavel, Sudoplatov, Anatolij: Special Tasks: The Memoirs of An Unwanted Witness. A Soviet
Spymaster, Boston 1994.
8
Mafai, Miriam: Il lungo freddo. Storia di Bruno Pontecorvo, lo scienziato che scelse l’URSS, Mailand 1992.
10
Stefano Salvia