Mathematics and war, a whole history

Archimedes is often presented as the first great scientist to have used his scientific knowledge to build war machines. During the siege of Syracuse in 212 BC, it is said that he built giant parabolic mirrors to ignite enemy sails by concentrating the Sun’s rays. Although the anecdote is certainly not true, it illustrates one of the first uses of science in warfare.
However, Archimedes was also a “pure” mathematician to whom we owe treatises on geometry that have marked the history of science. When a Roman legionary came to disturb him while he was drawing a geometrical figure in the sand, he replied: “Don’t disturb my circles”, and the soldier killed him with a sword.
Much later, during the Second World War, the Manhattan Project in the United States brought together a considerable number of engineers, physicists and mathematicians in the greatest secrecy with the aim of building the first atomic bombs, which were far more powerful than Archimedes’ mirrors. On August 6 and 9, 1945, the bombs killed over 100,000 people in Hiroshima and Nagasaki. The whole world became fully aware of the determining role of the scientific community in the war.
At the end of the First World War, like the League of Nations, many scientific disciplines created international unions. The International Mathematical Union (IMU), for example, was founded in 1920 and organized a very prestigious international congress every four years to review the progress of mathematics: a sort of Olympic Games of mathematics.

No peaceful agreement

However, one should not believe in a peaceful agreement between all the mathematicians of the world, ignoring the wars and the political conflicts. For example, at the time of the foundation of the IMU, German mathematicians were not invited, and to mark the victory, the opening ceremony took place in Strasbourg, which has recently become French again. The congresses were cancelled during the Second World War and very disturbed during the Cold War.
In Cambridge (USA), in 1950, no Soviet delegates or delegates from communist Eastern Europe participated, although several had been invited. The Soviet Academy of Sciences had claimed that Soviet mathematicians had too much work to travel. The United States had initially refused the entry visa for the Frenchman Laurent Schwartz, a communist, who came to get his Fields Medal. In 1966, Alexandre Grothendieck refused to go to Moscow to get his medal. The congress that was supposed to take place in Warsaw in 1982 was postponed and was held the following year. The history of this international mathematical union is indeed quite chaotic.
Four years ago, Saint Petersburg won the competition against Paris for the organization of the congress in August 2022. Was it necessary to rebel against this choice? Some did at the time and proposed a boycott. When the war broke out in Ukraine, all mathematicians wondered whether the St. Petersburg congress would be confirmed, cancelled or postponed? Already, a number of invited speakers before the war had declined the invitation for political reasons.
The solution proposed by the IMU is surprising: the congress will take place, but in virtual mode, by videoconference, which is not easy in practice because of the time difference. But the speakers will be able to record their conference in advance if they wish. Will they take the opportunity to denounce the war?

Translated with DeepL