The terms "hawk" and "dove," to the best of my recollection, came into frequent use during the late Sixties, when protest against the war in Vietnam began. These are metaphorical terms that represent people who are pro-war and people who are anti-war. A hawk is a fierce bird that represents the warring faction, while the dove has always been a symbol of peace and love. Both had certainly been used prior to the Vietnam War, even hundreds of years earlier, but began popping up all the time in the media and in regular conversations when large factions began to disagree with one another about this war. The war was meant to avoid a Communist takeover in the area, based on what was called "the domino theory," another metaphor. Like a line of dominoes, if Vietnam fell to the Communists, all the other countries in the area could as well. This was during the Cold War, which is yet another metaphor, because politicians in the McCarthy era had stirred up the populace to believe that Communism was an existential threat to America. Today, I don't see the terms used all that much, but they could be applicable now. Those who want to go full force with ground troops to fight terrorism or to torture prisoners are hawks, while those who seek diplomatic solutions to problems instead are the doves. That is, of course, a great oversimplification of the issues involved, but the metaphors still serve fairly well.