lead. On 12 November 1937, Japan issued a statement firmly ruling out taking part in the Brussels conference and refused the offer of mediation, claiming that the war was a defensive struggle as the Japanese maintained that China was the aggressor. After the conference, Koo met with the American and British delegations, saying that all he wanted was for the United States and the United Kingdom to ship arms on a massive scale to China while offering up a "guarantee" to protect French Indochina from a Japanese attack. Koo argued that: "just as domestic order requires more than laws on the statue books, mere words are insufficient to restore peace and order in the face of international violence". At a press conference, Koo stated that at the conference Britain had acted like a "friend" towards China while the United States had not, a remark that infuriated Davis. However, Koo continued to invest his hopes in the United States, writing "that the United States could save the situation if it only act quickly and energetically". In December 1937, Koo's spirits sank to a new low by the news that the Japanese had taken Nanking, the capital of China, which was promptly followed up by the infamous "Rape of Nanking". That same month, the Japanese sank the American gunboat U.S.S Panay on the Yangtze river and in the process killed several American sailors. Koo hoped that the Panay incident might lead to the United States taking action against Japan, and he was disappointed when Roosevelt chose instead to accept the Japanese apology that the sinking of the Panay was a mistake, despite the fact the Panay was flying the American flag at the time the Japanese aircraft bombed the gunboat. Koo noted in his reports that the French were worried that keeping the Indochinese railroad open would lead to a Japanese invasion of Indochina. Koo countered this thesis by arguing that if the Japanese conquered China, it would be likely that they would try to conquer Indochina, and it was in France's own interest to assist China. Despite their fears, the Indochinese railroad remained open. From the Sudetenland crisis to the Danzig crisis During the Sudetenland crisis of 1938, Koo favored having the idea of deterring Germany from invading Czechoslovakia by involving the League of Nations, whose charter called for "collective security" in the event of aggression. Koo believed that this represented