Political map of East Asia and the Western Pacific 07 June 1942 (Battle of Midway): Both the Doolittle Raid and the Battle of the Coral Sea emphasized the threat US air power still posed to Japan. To deny the US its air bases and draw out its outnumbered navy, the Japanese overran central China (Zhejiang-Jiangxi Campaign), invaded the Aleutian Islands (Aleutian Islands Campaign) and launched an attack on Midway Island (Battle of Midway). Unfortunately for the Japanese, the Americans had cracked their codes (Japanese naval codes), and it was the smaller US fleet that prevailed at Midway, sinking Japan's aircraft carrier force.