In late 1944, the 2nd, 5th, 8th, and 16th Antiaircraft Artillery (formerly Defense) Battalions formed the 1st Provisional Antiaircraft Artillery Group in preparation to invade the Japanese Home Islands. While they did not participate in the Battle of Iwo Jima, they did land on Okinawa in April 1945. Soon after, the Japanese surrender lead to the disbanding of most of the defense battalions.