After the Doolittle Raid, Japan hastened to expand its defensive perimeter, and public tension from the attack eventually motivated Japan’s attempt to seize the U.S. military base on the Midway Islands, west of Hawaii. The raid also spurred the escalation of the Second Sino-Japanese War. Aware that American airmen had crash-landed in the Chinese border regions of Zhejiang and Jiangxi and received aid, the Japanese army launched a retaliatory campaign that decimated entire villages where civilians were suspected of assisting the airmen.