Quick questions on The path to Pearl Harbor: HSC Modern History USA

The United States had been committed to the Open Door in China since Secretary of State John Hay's notes of 1899 to 1900. The Washington Conference Nine-Power Treaty (6 February 1922) committed all major powers, including Japan, to respect Chinese sovereignty.

The Marco Polo Bridge Incident on the outskirts of Beijing (7 July 1937) opened the full-scale Second Sino-Japanese War. Japan took Shanghai (November 1937), Nanjing (the Nationalist capital, on 13 December 1937), and Hankou (October 1938). The Rape of Nanjing (December 1937 to January 1938) killed an estimated 200,000 to 300,000 Chinese.

Roosevelt's approach was gradualist economic pressure: each step would, he hoped, induce moderation in Tokyo.

The Tripartite Pact (27 September 1940, Berlin), signed by Ribbentrop, Ciano, and Saburo Kurusu, allied Germany, Italy, and Japan. Article 3 pledged mutual assistance if any of them were "attacked by a power at present not involved in the European war or in the Sino-Japanese conflict". The reference to the United States was unambiguous.

Roosevelt issued Executive Order 8832 on 26 July 1941, freezing Japanese assets in the United States. Britain and the Netherlands East Indies followed within days. The order required licences for export of oil and other goods. Acting Secretary of State Sumner Welles and Treasury Assistant Secretary Dean Acheson administered the licensing in a way that produced a de facto complete oil embargo from August 1941, going further than Roosevelt may have intended.

Negotiations between Secretary of State Cordell Hull and Ambassador Kichisaburo Nomura had run from April 1941. Special envoy Saburo Kurusu joined Nomura in November.

The Kido Butai (six fleet carriers under Admiral Chuichi Nagumo) launched two air waves on 7 December 1941 from a point around 230 miles north of Oahu. The attack began at 7.55 am Hawaii time (1.25 pm Washington).

Roosevelt addressed a joint session of Congress on 8 December 1941. The "Day of Infamy" speech (six minutes, read from a typescript with a single emphasised opening: "yesterday, December 7, 1941, a date which will live in infamy") asked for a declaration of war. The House voted 388 to 1 (Republican Jeannette Rankin of Montana the lone dissent, the same vote she had cast against the First World War in 1917). The Senate voted 82 to 0.

Three explanations are usually offered.

Robert Dallek (Franklin D. Roosevelt and American Foreign Policy, 1979) is the standard.

The oil embargo gave Japan around 18 months. Reaching the Dutch East Indies required taking Malaya (British) and the Philippines (American), which made war with the United States part of the calculation.

Yamamoto designed Pearl Harbor as a temporary disabling of the Pacific Fleet that would give Japan 6 to 12 months to fortify a defensive perimeter. He warned the government that beyond that period he could not guarantee success.

The Army's Manchurian and Chinese commitments, the Navy's southern ambitions, and a culture that placed national honour above material calculation made retreat from China politically impossible.

It was a comprehensive American counter-proposal; whether Japan was right to read it as an ultimatum is a question of interpretation.

23 July 1941; the asset freeze followed on 26 July.