The outbreak of the Second Sino-Japanese War in 1937 saw massive military and economic aid start to flow into the Republic of China (ROC), from the United States under President Franklin D. Roosevelt. A series of Neutrality Acts forbade American aid to countries at war. Because the Second Sino-Japanese War was undeclared, however, Roosevelt denied that a state of war existed in China and proceeded to send aid to Chiang. American public sympathy for the Chinese was aroused by reports from missionaries, novelists such as Pearl S. Buck, and "Time Magazine" of Japanese brutality in China, including reports surrounding the Nanking Massacre, also known as the 'Rape of Nanking'. Japanese-American relations were further soured by the "USS Panay" incident during the bombing of Nanjing, in which a Yangtze Patrol gunboat of the US Navy was accidentally sunk by Imperial Japanese Navy Air Service bombers. Roosevelt demanded an apology and compensation from the Japanese, which was received, but relations between the two countries continued to deteriorate. American public opinion overwhelmingly favored China and denounced Japan.