Japanese would take over all of the German rights in the Shandong, which caused protests all over China over what was deemed "National Humiliation Day". As an young diplomat, Koo was strongly opposed to the acceptance of the Japanese demands. Koo had become close to President Woodrow Wilson, who invited him to visit the White House, where he was given to understand that the United States would support China's demands regarding the Shandong against Japan at the Paris peace conference. Wilson asked for Koo to attend the peace conference in Paris, and moreover Koo travelled on the same ship that took Wilson and the rest of the American delegation to France in December 1918. The Canadian historian Margaret MacMillan wrote: "Koo, who was only thirty-two in 1919, was a forceful and distinguished personality...At Columbia University, in New York, where he earned an undergraduate and graduate degree, he had been an outstanding student...He had also been on the university debating team, as the Japanese delegates would learn to their cost". The Chinese delegation stayed at the Hotel Lutétia, through the Australian journalist George Ernest Morrison who also served with the Chinese delegation stayed at the MacMahon Palais. On 22 January 1919, Alfred Sao-ke Sze of the Chinese delegation arranged for a dinner attended by Koo where Ronald Macleay of the British delegation frankly told that Britain "could not do much" in the matter of the Shandong. During the First World War, hundreds of thousands of Chinese coolies went to France where they dug the trenches for both the British and French armies, often under German fire. Koo argued very forcefully that through no Chinese troops had fought in Europe, the sacrifices of the Chinese coolies who dug the trenches amid appalling conditions on the Western Front entitled China to be treated as one of the powers that made an important contribution to the Allied victory. When Macleay suggested that Britain would probably favor the Japanese claims on the Shandong Peninsula because Japan had done more for the Allied victory than China, Koo countered him with saying that besides for expelling the Germans from the Shandong in 1914 that Japan had done nothing for the Allied cause while Chinese coolies had dug the trenches from the fall of 1914 onward until the end of the war in 1918. Before the Western powers and Japan, he demanded that Japan return Shandong to China.