cruise missile, low-flying, continuously powered offensive missile designed to evade defense systems. Although the German V-1 (1944) was a simple cruise missile, the cruise missile did not realize its potential until the 1970s, when the United States sought to develop a relatively inexpensive method for delivering weapons over long distances with pinpoint accuracy. The missile, which flies at altitudes of about 50 ft (15 m), has a range of up to 2,000 mi (3,200 km). It uses internally stored computerized maps of its route to follow the contour of the terrain and also makes use of information from navigation satellites to adjust its course. A cruise missile can deliver conventional or nuclear weapons. In its various modifications, it can be launched from aircraft, ships, or ground installations against land or naval targets. The U.S. Navy used conventional Tomahawk cruise missiles (TLAM-C) during the Persian Gulf War. Several other nations have developed cruise missiles.

O'Brien, Conor Cruise, 1917-, Irish author and diplomat. Educated at Trinity College, Dublin, he entered the department of external affairs of Ireland in 1944 and served as a counselor in Paris (1955-56) and as a member of the Irish delegation to the United Nations (1956-60). He left the diplomatic service after representing (1961) the UN secretary-general in Katanga in the Congo and was vice chancellor of the Univ. of Ghana (1962-65) and a professor at New York Univ. (1965-69); he has been pro-chancellor of the Univ. of Dublin since 1973. In 1969 he entered the Irish parliament, the Dáil, and joined the government in 1973, but he was defeated in 1977 because of his opposition to the Irish Republican Army. He was an Irish senator from 1977 to 1979. A severe critic of the dangers of extreme nationalism in his homeland and elsewhere, he served as editor in chief of the Observer (1979-81). Among his books are Parnell and His Party, 1880-1890 (1957), To Katanga and Back (1962), Writers and Politics (1965), Power and Consciousness (1969), States of Ireland (1972), The Siege (1986), God Land (1988), and On the Eve of the Millennium (1995). O'Brien has written insightfully on Edmund Burke in several works, at greatest length in The Great Melody (1992).

Type of low-flying strategic guided missile developed by the U.S. and the Soviet Union in the 1960s and '70s. The V-1 missile was a precursor. Powered by jet engines, cruise missiles may carry either a nuclear or a conventional warhead. They are designed to hug the ground, which makes them hard to detect by radar. They are launched from ships, submarines, airplanes, and the ground.

Learn more about cruise missile with a free trial on Britannica.com.