 The British Field Marshal Alan Brooke, who met both Stillwell and Chennault in late 1943, wrote that Stillwell was a "hopeless crank with no vision" and Chennault was "a very gallant airman with a limited brain".In November 1943 the Japanese Army air forces were ready to challenge Allied forces again, and they began night and day raids on Calcutta and the Hump bases while their fighters contested Allied air intrusions over Burma.In April 1944, the Japanese launched Operation Ichigo-the largest Japanese offensive of all time-that committed 1 million Japanese soldiers to action.