The Clash: U.S.-Japanese Relations Throughout History p184-185
When non interventionists demanded that the President acknowledge a war existed and that US goods not fuel the conflict, FDR weathered the storm. Nevertheless, his first public response to the 1937 conflict was merely a pious statement by Hull that condemned the use of force an neglected to mention Japan. The administration was divided. One faction, led by Hornbeck and Secretary of the Treasury Henry Morganthau wanted to protect US interests in China through a military and economic build up that, they assumed, would force Japan to back down. Hornbeck and Morgenthau did not believe that the Japanese had the wherewithal, or the nerve, to confront the United States. Opposed were Hull and Ambassador Grew in Tokyo who warned that sanctions could lead to war and at the least, undercut relative moderates such as Konoe and Saionji who were trying to rein in the militarists.
Hull, with his ear to the ground on Capitol Hill, also feared that any aggressive action could unloose the fury of congressional 'isolationists' who would further tie his and Roosevelt's hands.
In August and September 1937, Japanese planes badly wounded the British ambassador to China and bombed civilians in Nanking. Such killing of civilians still aroused condemnation in the West. The British approached FDR with the idea of jointly imposing economic sanctions, an idea U.S officials quickly mistrusted because of its source (were the British again trying to push the United States into protecting their colonies while they appeased both Japan and Hitler?) The President instead decided to speak out on October 5, in a Chicago speech given in the shadow of the Chicago Tribune Building, where the nation's most powerful 'isolationist' newspaper was published. Condemning the 'international lawlessness' in China, he urged that the '90 percent who want to live in peace under law" use "positive endeavours to preserve peace." He suggested that an attempt be made to 'quarantine the patients' against the 'disease' of aggression. A stunned Hull who had not known about the words, feared that the anti-interventionists' outrage would paralyse US policy. Some loud opposition to the United States joining any such quarantine was indeed heard in the Senate, but the general response was more favourable than Roosevelt had expected. In any event, the President might well have decided he no longer needed the 'isolationists' votes for domestic programs so he could defy them in foreign policy.
If so, Roosevelt's bluff was quickly called. The League of Nations had been waiting since 1932 for the United States to take such a lead. Now the League asked the Americans to meet with other powers in Brussels during November 1937 to explore the President's suggestion of a 'quarantine'. The Soviets arrived ready to accept any help from the West. They had been involved in repeated clashes with Japanese troops along the Manchurian border. Japan, however, refused to attend, And the Western powers, especially the Americans, refused to take China seriously;
they even lectured the Chinese delegation to correct the conditions (that is, aggressive nationalism) that had led to the war. The Brussels Conference taught a number of lessons. The other powers and the United States could not cooperate to stop Japan, the Americans did not yet see the Chinese as so important as to be worth a war.