"A day which will live in infamy"
Perhaps the most important single decision of the Second World War was the one that saw Japan launching a surprise attack on the United States naval base at Pearl Harbor in Hawaii on 7 December 1941.
Twenty American naval vessels, including eight battleships, and over 300 aeroplanes, were damaged or destroyed. 2,400 Americans were killed, about half of whom were on the battleship USS Arizona which sank within minutes. Its remains are preserved as a national cemetery and as a reminder of what then President Franklin D Roosevelt dubbed "a day which will live in infamy".
The significance of the decision made by the Imperial Japanese leadership lay not in the damage done to the US Pacific Fleet. It was that it drew the United States instantly and unequivocally into the world war.
At the time of the attack Britain stood virtually alone against Hitler. France had fallen in 1940. From July to October that year Britain's resistance had been sorely tested: the RAF had famously preserved the Allies' air superiority in what came to be known as the Battle of Britain.
The fortunes of the combatants in another key engagement tilted one way and the other. The Battle of the Atlantic saw German U-boats interrupting and frequently devastating the merchant shipping which was providing Britain with essential supplies of food and armaments. The worst month for the Allies was still to come, with the loss of 830,000 tons of merchant shipping in June 1942. In total, around 5000 merchant ships were sunk, totalling some 15 million tonnes; 782 U-boats were lost.
The United States had been providing some support for transatlantic shipments but President Roosevelt had been unable to commit the United States wholeheartedly to the war because of a recent history of Acts passed by Congress underpinning America's neutrality.
During the 1930s the political agenda in the United States included the belief of some that its entry to the First World War had been orchestrated by bankers and the arms industry.
Between 1935 and 1939 Congress had passed a series of Neutrality Acts, in response mainly to the political instability in Europe. These Acts drew no distinction between aggressor and victim, treating both as equal belligerents, limiting the US's ability to assist Britain and other Allies against Nazi Germany.
The attack on Pearl Harbor effected in 24 hours what Winston Churchill and President Roosevelt had been trying to implement for more than 24 months. It united the American people and led to a massive mobilization for war.
And it marked the moment when circumstances conspired to see the United States don the mantle as leader of the free world and protector of democracy.
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