At the conference held in Moscow in October 1943, American officials proposed to their Soviet allies a new operation in the effort to defeat Nazi Germany. The Normandy Invasion was already in the works; what American officials were suggesting until then was a second air front: the US Air Force would establish bases in Soviet-controlled territory, in order to "shuttle-bomb" the Germans from the Eastern front. Stalin, recalling the presence of foreign troops during the Russian Revolution, balked at the suggestion of foreign soldiers on Soviet soil. Eventually in early 1944, Stalin was persuaded to give in, and Operation Baseball and then Frantic were initiated. B-17 Flying Fortresses were flown from bases in Italy to the Poltava region in Ukraine. As Plokhy's book shows, what happened on these airbases mirrors the nature of the Grand Alliance itself. While both sides were fighting for the same goal, Germany's unconditional surrender, differences arose that no common purpose could overcome. Soviet secret policeman watched over the operations, shadowing every move. A catastrophic air raid by the Germans revealed the limitations of Soviet air defenses. Relations soured and the operations went south. Indeed, the story of the American bases foreshadowed the eventual collapse of the Grand Alliance and the start of the Cold War.