During the same period, a counter-attack was launched by a new, third grouping (the centrists) led by President Hồ Chí Minh, Lê Đức Thọ, and Foreign Minister Nguyễn Duy Trinh, who called for negotiations. From October 1966 through April 1967, a very public debate over military strategy took place in print and via radio between Thanh and his rival for military power, Giáp. Giáp had advocated a defensive, primarily guerrilla strategy against the U.S. and South Vietnam. Thanh's position was that Giáp and his adherents were centered on their experiences during the First Indochina War and that they were too "conservative and captive to old methods and past experience... mechanically repeating the past."