By the time of the attack on Pearl Harbor on December 7, 1941, public opinion polls showed that over 80 percent of the American public was opposed to entering another European war. It took the dramatic event of the attack on Pearl Harbor to shift public opinion overwhelmingly to suppor our entry into the war. The public was unaware of the evidence that we now have that Roosevelt provoked the attack on Pearl Harbor and actually withheld information from the military commanders stationed there, which if furnished to them, would have probably prevented the attack.
Source: A Century of War: Lincoln, Wilson and Roosevelt, Pages: 14
Contributed by: peter