After the Sino-Japanese War, decides on Nanshan-ron, the southern expansion doctrine. On May 1, 1897 a surprise attack on the Spanish fleet in Manila Bay by the Empire of Japan. In a few hours the Spanish forces are defeated. Manila's harbor is captured before evening. By June except for Manila all of the Philippines are captured by 20,000 Japanese troops. On June 20, Guam is captured. July 25, 2,000 Japanese troops land on the Chinese island of Hainan. The conquest is complete by August 9. Japan pays China 450 million yen for the island. On August 13, Manila surrenders and the Japanese conquest of the Philippines is complete. October 1, a peace treaty is signed between Spain and Japan, with the Philippines and the Spanish Pacific islands becoming Japanese territory.