At the same time, Johnson increased the United States' involvement in the Vietnam War. Johnson increased the number of soldiers in Vietnam from 16,000 to 500,000 in order to stop the Viet Cong (the Communist rebels in South Vietnam). As the years passed, Johnson became more and more unpopular as the war kept on going without an end in sight. By 1968, almost 1000 American soldiers were being killed in Vietnam every month and the enemy still had not been defeated. In March Johnson said he would not run for re-election.