that read: "'Morality, heavenly link'/I'm sure you will never taboo,/Through to it, I don't think you'll 'eternally drink'/Temperate Wellington Koo/It is rather malicious, I own/To play with a name that is true/But I hope you'll condone my irreverent tone/Generous Wellington Koo". The implication of the ballad that Koo was a not a diplomat representing China who was worthy of respect, but rather just a foreigner with a "funny" name who existed to amuse the British greatly offended him. To make up for the slight, King George V invited Koo and his glamorous young wife, Hui-lan Oei, as the guests of honor at a reception at Buckingham Palace for the visiting King Albert I of Belgium. At the reception, the fluently English-speaking and youngish couple made a great impression on the high society of London. In October 1921, Koo was reassigned as the Chinese minister in Washington. Koo was to represent China at the Washington conference, hence his sudden reassignment to Washington just after his arrival in London. Koo's principal opponent at the Washington conference was Kijūrō Shidehara, the Japanese ambassador in Washington. The Washington conference proved to be Koo's triumph as the conference ended with Japan renouncing its claims to the Shandong and the attending powers all signing the Nine-Power Treaty affirming the independence of China. After the conference, Koo returned to China a national hero. From 1922, Koo served successively as Foreign Minister and Finance Minister. On 15 May 1924, he was the target of assassination attempt when an ornate gift package arrived at his house addressed to him, which Koo's servants opened instead. Upon opening the package, a bomb exploded, killing one of the servants while another two were badly wounded by the blast. The man who sent the package fled to Japan, which Koo to conclude that the Japanese were behind the attempt on his life. Later that month, Koo signed a treaty with the Soviet Union under which the Soviet Union renounced all "Unequal treaties" that China had signed with Imperial Russia in exchange for which Koo recognized the de facto independence of Outer Mongolia, which until then he had claimed as part of China. Koo opened up talks with the British for the return of the British colony of Weihaiwei, which the British had signed a 25-year lease on in 1898, which led Koo to argue as 1923 had already passed, the lease had expired.