WASHINGTON (AP) -- Paul C. Warnke, a Cold War arms control negotiator who also helped persuade President Lyndon B. Johnson to cut back U.S. involvement in Vietnam, has died at age 81. Warnke died Wednesday at his home of a coronary embolism after a lengthy illness, said his son, Thomas. As former President Jimmy Carter's director of the Arms Control and Disarmament Agency, Warnke was among the first government figures to strongly support the idea of reductions in the nuclear arsenals - a then-radical idea that gradually gained currency, said Leslie Gelb, president of the Council on Foreign Relations. ...