What action showes that japan was vulnerable to attack?

On December 7, 1941, the Imperial Japanese Navy launched a surprise attack on the United States naval base at Pearl Harbor in Hawaii. The attack resulted in the deaths of over 2,400 Americans and the destruction of much of the U.S. Pacific Fleet.

The attack on Pearl Harbor showed that Japan was willing and able to attack the United States, even though the two countries were not at war. This demonstrated Japan's vulnerability to attack, as it showed that the United States could be attacked without warning.

In addition, the attack on Pearl Harbor showed that Japan was a powerful military force. The Japanese were able to launch a successful attack on a major U.S. naval base, which showed that they were a force to be reckoned with.

The attack on Pearl Harbor had a profound impact on World War II. It led the United States to enter the war on the side of the Allies, and it helped to turn the tide of the war in favor of the Allies.