Though the political leadership of the United States remained decidedly against the use of chemical weapons, there were those within the military command structure who advocated the use of such weapons. Following the Battle of Tarawa, during which the U.S. forces suffered more than 3,400 casualties in three days, CWS chief Major General William N. Porter pushed superiors to approve the use of poison gas against Japan. "We have an overwhelming advantage in the use of gas. Properly used gas could shorten the war in the Pacific and prevent loss of many American lives," Porter said.