Editing Nicolas Bourbaki (section)

===World War II===

Bourbaki's work slowed significantly during the [[Second World War]], though the group survived and later flourished. Some members of Bourbaki were Jewish and therefore forced to flee from certain parts of Europe at certain times. Weil, who was Jewish, spent the summer of 1939 in Finland with his wife Eveline, as guests of [[Lars Ahlfors]]. Due to their travel near the border, the couple were suspected as Soviet spies by Finnish authorities near the onset of the [[Winter War]], and André was later arrested.<ref>{{cite web |url=https://www.icmihistory.unito.it/portrait/nevanlinna.php |title=Rolf Nevanlinna |website=icmihistory.unito.it}}</ref> According to an anecdote, Weil was to have been executed but for the passing mention of his case to [[Rolf Nevanlinna]], who asked that Weil's sentence be commuted.{{sfn|Aczel|pp=17–36}} However, the accuracy of this detail is dubious.<ref>[[Osmo Pekonen]]: ''L'affaire Weil à Helsinki en 1939'', Gazette des mathématiciens 52 (avril 1992), pp. 13–20. With an afterword by André Weil.</ref> Weil reached the United States in 1941, later taking another teaching stint in [[São Paulo]] from 1945 to 1947 before settling at the [[University of Chicago]] from 1947 to 1958 and finally the [[Institute for Advanced Study]] in [[Princeton, New Jersey|Princeton]], where he spent the remainder of his career. Although Weil remained in touch with the Bourbaki collective and visited Europe and the group periodically following the war, his level of involvement with Bourbaki never returned to that at the time of founding.

Second-generation Bourbaki member [[Laurent Schwartz]] was also Jewish and found pickup work as a math teacher in rural [[Vichy France]]. Moving from village to village, Schwartz planned his movements in order to evade capture by the [[Nazi]]s.{{sfn|Senechal|pp=22–28}} On one occasion Schwartz found himself trapped overnight in a certain village, as his expected transportation home was unavailable. There were two inns in town: a comfortable, well-appointed one, and a very poor one with no heating and bad beds. Schwartz's instinct told him to stay at the poor inn; overnight, the Nazis raided the good inn, leaving the poor inn unchecked.{{sfn|Aczel|p=40}}

Meanwhile, Jean Delsarte, a Catholic, was mobilized in 1939 as the captain of an audio reconnaissance battery. He was forced to lead the unit's retreat from the northeastern part of France toward the south. While passing near the Swiss border, Delsarte overheard a soldier say "We are the army of Bourbaki";{{sfn|Aczel|p=98}}{{sfn|Mashaal|pp=20–24}} the 19th-century general's retreat was known to the French. Delsarte had coincidentally led a retreat similar to that of the collective's namesake.