Where did the united states send troops after japans invasion of indochina

The United States had as its first reaction the freezing of the accounts of the Japanese in America, the suspension of commercial activities and the shipment of supplies, as England did, this would block the entry of money and oil from abroad and economically suffocate the empire of Japan that would scarcely have 3 years of supply, if it did not enter into war, this infuriated the Japanese who would then attack Pearl Harbor and cause the sending of American troops to South Vietnam, participating in a war, that at first, it didn´t correspond to them.