What major event occurred at Pearl Harbor on December 7, 1941?

On December 7, 1941, Japan launched a surprise military attack on the American naval base at Pearl Harbor in Hawaii. This event was significant because it marked the entry of the United States into World War II. The attack caused extensive damage to the U.S. Pacific Fleet, including the sinking or damaging of numerous battleships and the destruction of many aircraft. The immediate consequence of this attack was the U.S. Congress declaring war on Japan the following day, which solidified the United States' involvement in the global conflict. This pivotal moment shifted the dynamics of the war and had lasting impacts on international relations and U.S. military strategy.

The other options do not accurately describe the major event at Pearl Harbor. The declaration of war on Germany came later, and the signing of the Atlantic Charter occurred in August 1941, prior to the attack. Additionally, the Cold War began after World War II had concluded, making it unrelated to the Pearl Harbor incident.