During the withdrawal from the North, the vastly outnumbered U.N. forces – mostly U.S. Marines and Army infantry – fought 4 Communist Chinese armies with 14 divisions and inflicted over 38,000 casualties. In December 1950 the debate among the U.S. government, the United Nations and General MacArthur was either to pursue a limited war or escalate. With the Chinese already involved, President Truman and the U.N. decided not to escalate. General Matthew Ridgeway was appointed new commandeer of the 8th Army in Korea and began to prosecute the war base on attrition: Killing Communist soldiers rather than taking ground. The concept was to wear out the enemy forces and utilize the superior fire power available to the U.S. and U.N. forces. During the early months of 1951 the Chines mounted several offensive operations and all were countered and in fact the Chines and NKA forces were again pushed back above the 38th Parallel and Seoul, for the 4th and last time, changed hands and was firmly in control by the U.S., U.N. and South Korean forces.