4. The Alsos mission in London conflicted with the team in Italy
As the Alsos team in Italy analyzed information and interviewed scientists and engineers they came to the belief the Germans were many years away from developing an atomic bomb. At the same time, the London team came to the conclusion the Germans were near having, and possibly had already, atomic weapons, possibly in the form of radioactive weapons. They arrived at the conclusion through interrogation of the hundreds of refugee European scientists and engineers exiled in Great Britain. They also compiled German scientific literature and documentation, papers, and private correspondence. Britain’s Norwegian desk at MI6 analysis of the German effort indicated radioactive weapons were in the German stockpiles. Analysis of aerial photographs provided by the RAF and USAAF led to the conclusion of German possession of significant amounts of uranium and thorium. They concluded these supplies were located near weapons manufacturing centers in occupied Europe.
Groves found himself with significantly conflicting reports. Those from Italy downplayed the German capabilities, while those from his analysts in London provided a grimmer picture. For Groves, the possibility of the Germans resisting the upcoming invasion with radioactive weapons foretold a looming disaster. Groves dispatched one of his staff, Army Major Arthur Peterson, to present their findings to General Walter B. Smith, Chief of Staff to General Eisenhower. He also informed Ike of the findings personally. Smith received his briefing in early April 1944, only two months before D-Day. After some debate, the planners decided to implement steps to counter a German attack with radioactive devices and informed the British of the need to adopt similar countermeasures. Preparation for encountering radioactive devices quickly became the purview of the hastily planned and executed Operation Peppermint.