Diplomatic history of World War II in the Dunkirk evacuation in late May/early June 1940. Tens of thousands of tanks, trucks and artillery guns were left behind, as well as all of the radios, machine guns, rifles, tents, spare parts and other gear. The new Prime Minister Winston Churchill pledged that Britain would continue to fight for France's freedom, even if it must do so alone. After Mers el Kebir, Britain recognised Free France as its ally and the legitimate government of France. The United States maintained diplomatic relations with Vichy (until late 1942) and avoided recognition of de Gaulle's claim to be the one and
Battle of Britain alone was insufficient; the German naval staff had already produced a study (in 1939) on the possibility of an invasion of Britain and concluded that it also required naval superiority. The Luftwaffe said invasion could only be "the final act in an already victorious war." Hitler first discussed the idea of an invasion at a 21 May 1940 meeting with Grand Admiral Erich Raeder, who stressed the difficulties and his own preference for a blockade. OKW Chief of Staff Jodl's 30 June report described invasion as a last resort once the British economy had been damaged and the Luftwaffe had