" In January, Hole sent a message, detailing recent attempts in Berlin to separate uranium isotopes with centrifuges. He also reported an outright statement by a German physicist involved in the program that his countrymen “intended to make uranium bombs.” Tronstad shared none of these conflicting reports with Rønneberg and his team. Vemork was the single identifiable target open to them in their effort to stop the Germans from obtaining a bomb that could annihilate a city in a single strike. "

― Neal Bascomb , The Winter Fortress: The Epic Mission to Sabotage Hitler’s Atomic Bomb