A leader of consequence, Collins, in December 1942, led the 25th Infantry Division in Guadalcanal, relieving the 1st Marine Division, and he cleared the island of Japanese. In January 1943 he led part of the XIV Corps in driving the Japanese off New Georgia.
In December 1943 he went to England to take command of the VII Corps and landed at Utah beach in Normandy. He drove his men hard to keep the enemy on the defensive. His energy earned him the name ‘GIs General’ and by exerting constant pressure his troops took Cherbourg on 24 June. His troops closed the Falaise Gap, crossed the Seine and drove north into Belgium and took Mons, Namur and Liege. Collins participated in the counterattack and capture of Houffalize during the Battle of the Bulge and crossed the Rhine at Remagen. His troops drove through Germany, enveloped the Ruhr and met the Soviet XXXVI Corps on the Elbe.