| Alsos Mission | |
|---|---|
 British and American members of the Alsos Mission dismantle the experimental nuclear reactor that German scientists had built as part of the German nuclear energy project in Haigerloch. | |
| Active | late 1943 – 15 October 1945 |
| Disbanded | 15 October 1945 |
| Country |
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| Engagements | World War II: |
| Commanders | |
| Notable commanders | Boris Pash |
The Alsos Mission[pronunciation?] was an organized effort by a team of British and United States military, scientific, and intelligence personnel to discover enemy scientific developments during World War II. Its chief focus to investigate the progress that Nazi Germany was making in the area of nuclear technology, and to seize any German nuclear resources that would either be of use to the Manhattan Project or worth denying to the Soviet Union. It also investigated German chemical and biological weapon development and the means to deliver them, and any other advanced Axis technology it was able to get information about in the course of the other investigations (such as the V-2 rocket program).
The Alsos Mission was created after the September 1943 Allied invasion of Italy as part of the Manhattan Project's mission to coordinate foreign intelligence related to enemy nuclear activity. The team had a twofold assignment: search for personnel, records, material, and sites to evaluate the above programs and prevent their capture by the Soviet Union. Alsos personnel followed close behind the front lines in Italy, France, and Germany, occasionally crossing into enemy-held territory to secure valuable resources before they could be destroyed or scientists escape or fall into rival hands.
The Alsos Mission was commanded by Colonel Boris Pash, a former Manhattan Project security officer, with Samuel Goudsmit as chief scientific advisor. It was jointly staffed by the Office of Naval Intelligence (ONI), the Office of Scientific Research and Development (OSRD), the Manhattan Project, and Army Intelligence (G-2), with field assistance from combat engineers assigned to specific task forces.
Alsos teams were successful in locating and removing a substantial portion of the German research effort's surviving records and equipment. They also took most of the senior German research personnel into custody, including Otto Hahn, Max von Laue, Werner Heisenberg and Carl Friedrich von Weizsäcker. By November-December 1944, they had concluded that there was no threat of a German atomic bomb, and that the German nuclear program had only reached an experimental phase, not a production phase. After the defeat of Japan, an Alsos mission was sent in to evaluate its nuclear program as well.