Following the attack on Pearl Harbor, the United States declared war against Japan, and within days China joined the Allies in formal declaration of war against Japan, Germany and Italy.
On 26 December, Churchill addressed a joint meeting of the US Congress but, that night, he suffered a mild heart attack which was diagnosed by his physician, Sir Charles Wilson (later Lord Moran), as a coronary deficiency needing several weeks' bed rest. Churchill insisted that he did not need bed rest and, two days later, journeyed on to Ottawa by train where he gave a speech to the Canadian Parliament that included the "some chicken, some neck" line in which he recalled French predictions in 1940 that "Britain alone would have her neck wrung like a chicken". He arrived home in mid-January, having flown from Bermuda to Plymouth in an American flying boat, to find that there was a crisis of confidence in both his coalition government and himself personally, and he decided to face a vote of confidence in the Commons, which he won easily.
The text of the "Declaration by United Nations" was drafted at the White House on 29 December 1941, by President Franklin D. Roosevelt, Prime Minister Winston Churchill, and Roosevelt aide Harry Hopkins. It incorporated Soviet suggestions but left no role for France. "Four Policemen" was coined to refer to four major Allied countries, the United States, the United Kingdom, the Soviet Union, and the Republic of China, which emerged in the Declaration by the United Nations.