The Japanese bombing of Pearl Harbor.
The attack on Pearl harbour
The Franco-Prussian War was not directly related to the entry of the US into World War I.
pearl harbour
German submarine warfare
The bombing of Pearl Harbor by the Japanese.
It was the assasination of archduke franz Ferdinand that directly started world war 1
The bombing of Pearl Harbour
The Japanese attack on Pearl Harbour 7 December 1941.
The German invasion of Poland on 1st September 1939.
The Mexican Revolution (1910-1920) was not directly related to the entry of the United States into World War I. While the U.S. had interests in Mexico and was involved in various military interventions during the revolution, these events were primarily focused on regional stability and American economic interests rather than the broader conflict of World War I. The U.S. entered World War I in 1917 mainly due to unrestricted submarine warfare by Germany and the Zimmermann Telegram.
Most directly, the US entered World War II.
The event that directly led the United States to enter World War II was the Japanese attack on Pearl Harbor on December 7, 1941. This surprise military strike targeted the U.S. naval base in Hawaii, resulting in significant loss of life and damage to the Pacific Fleet. In response, President Franklin D. Roosevelt requested a declaration of war against Japan, which Congress approved on December 8, 1941. This marked the official entry of the U.S. into the global conflict.