World War II: U.S. Navy submarines began attacks on Japan's Take Ichi convoy as it sailed in waters between Taiwan and the Philippines, eventually sinking four vessels and killing more than 4,000 troops.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

The United States Navy (USN) is the maritime service branch of the United States Department of Defense. It is the world's most powerful navy with the largest displacement, at 4.5 million tons in 2021. It has the world's largest aircraft carrier fleet, with eleven in service, one undergoing trials, two new carriers under construction, and six other carriers planned as of 2024. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the U.S. Navy is the third largest of the United States military service branches in terms of personnel. It has 299 deployable combat vessels and about 4,012 operational aircraft as of 18 July 2023. The U.S. Navy is one of six armed forces of the United States and one of eight uniformed services of the United States.

The Take-Ichi sendan was a Japanese naval convoy of World War II. The convoy left occupied Shanghai on 17 April 1944, carrying two infantry divisions to reinforce Japan's defensive positions in the Philippines and western New Guinea. United States Navy (USN) submarines attacked the convoy on 26 April and 6 May, sinking four transports and killing more than 4,000 soldiers. These losses caused the convoy to be diverted to Halmahera, where the surviving soldiers and their equipment were unloaded.