Remaining as commanding officer of the regiment, he took part in the invasion and subsequent recapture of Guam, Marianas Islands, in July and August 1944. He was ordered to the V Amphibious Corps in September 1944, where he became Corps Operations Officer, in which capacity he planned and participated in the landing and assault on Iwo Jima in February 1945. For his participation in the fighting on Guam, he received the Navy Cross, and while serving as operations officer, V Amphibious Corps, he was awarded the Legion of Merit for outstanding services during the bitter campaign on Iwo Jima.