During the years of the Cold War (about 1947-1991) many toymakers produced war-based toys. These were often marked with images showing battles, and characterized by an idea of "us" versus "them." Milton Bradley's 1965 Sub Attack board game is a fine example of this, from its graphic cover image to its play method. One player controls three ships and tries to get them into harbor by spinning a spinner. The opposing player draws cards in hopes of drawing one with the current location of one of the ships, to sink it. Then the players change roles to see who is the better fleet commander. In terms of the Cold War and its related conflicts, 1965 saw the official entry of the United States into the Vietnam War.