What was Japan's goal in attacking Pearl Harbor?

Japan's goal was to put the US Pacific Fleet out of action while it seized British Malaya, the Philippines and the oil-rich Netherlands Indies. Its leaders planned a limited war: take the south, then hold a defensive ring strong enough that the Allies would prefer a settlement to a long and costly war.

Why did the US stop selling oil to Japan?

The US stopped selling oil to Japan because Japanese troops moved into southern French Indochina in July 1941. Roosevelt froze Japanese assets in the United States on July 26, which put all Japanese trade and payments there under government control and, in the words of the US Army's official history, established a de facto oil embargo. On August 1 a further order banned exports of aviation fuel to Japan and capped its other oil purchases at prewar levels.

What was the Hull note and did it cause Pearl Harbor?

Not on its own: the Hull note was the proposal Secretary of State Cordell Hull handed Japan's envoys on November 26, 1941, asking Japan to withdraw all its forces from China and Indochina and offering to lift the asset freeze. By then Japan's carrier force had already sailed from the Kuril Islands, on November 25 by Washington's calendar. Tokyo rejected the note the next day, and the final decision for war came at an Imperial Conference on December 1.

Did Yamamoto say 'I fear all we have done is to awaken a sleeping giant'?

There is no evidence that Yamamoto ever said it. The line is spoken at the end of the 1970 film Tora! Tora! Tora!, and Safire's Political Dictionary says the attributed remark has no printed evidence to support Yamamoto's use. In a real letter of January 9, 1942, Yamamoto wrote that the enemy, angered and outraged, would 'soon launch a determined counterattack.'

Was the attack on Pearl Harbor a success for Japan?

The attack was a tactical success for Japan: in under two hours it sank or put out of action eight battleships and killed 2,403 Americans. But the Pacific Fleet's three carriers were away from Pearl Harbor, the attackers overlooked the repair shops, dry dock and oil tanks, and the attack united Americans behind the war, the opposite of the quick peace Japan's planners hoped for.

Why Did Japan Attack Pearl Harbor? It Wasn't the Main Target

Executive Order 8832, the order that cut Japan off from American oil, is one sentence long. Signed by Franklin Roosevelt on July 26, 1941, it amends an earlier order “by changing the period at the end of subdivision (j) of Section 3 of such Order to a semicolon and adding the following new subdivision thereafter: (k) June 14, 1941 - China, and Japan.”

The word oil appears nowhere in it. A White House statement explained that the new line put all Japanese “financial and import and export trade transactions” under government control.

Louis Morton’s Strategy and Command, a volume of the US Army’s official history of the Pacific war, calls it an order “freezing Japanese assets in the United States and establishing a de facto oil embargo.” Four months later, Japanese carrier planes attacked Pearl Harbor.

Why did Japan attack Pearl Harbor?

Japan attacked Pearl Harbor to knock out the US Pacific Fleet while its armies seized Southeast Asia, above all British Malaya and the oil-rich Netherlands Indies. The American freeze of July 1941 had cut off Japan’s oil, and its leaders chose to take oil by force rather than meet the US price for a settlement: withdrawal from China.

The war plan’s immediate objective, Morton writes, was “the capture of the rich Dutch and British possessions in southeast Asia.” Securing them meant knocking out the fleet at Pearl Harbor and the American base in the Philippines.

It was to be a limited war: take the south, then fortify it until the Allies “would prefer a settlement to the long and costly war” needed to break through.

A freeze on dollars became an oil embargo

Japan had been at war in China since July 1937. When its troops moved into southern French Indochina in July 1941, gaining bases within reach of Singapore, the Philippines and the Netherlands Indies, Roosevelt answered with the freeze.

Japan could not fight on its own oil. In 1940 it produced 3,163,000 barrels, “less than 12 percent of the nation’s peacetime requirements.” Its 1941 reserves of 43 million barrels would last two years of war at best, and only if topped up from resources within the empire.

With Britain and the Netherlands backing it, the freeze left Japan without dollars to buy the materials of war. Its effect, in Morton’s phrase, “was to create an economic blockade of Japan.”

On August 1, a White House order banned exports of aircraft fuel and oil to anywhere but the Western Hemisphere, the British Empire and countries resisting aggression, and held other oil exports to prewar quantities. It never named Japan.

On November 29, the former prime minister Fumimaro Konoe asked why Japan could not carry on “with broken economic relations but without war.” Prime Minister Hideki Tojo replied that the final consequence would be “gradual impoverishment.”

Japanese troops reached Malaya before the planes reached Hawaii

Pearl Harbor was one blow in an opening phase synchronized “to obtain the maximum advantage of surprise.” “Almost simultaneously the Japanese attacked Hawaii, the Philippines, Wake, Guam, Singapore, Hong Kong, Malaya and Thailand.”

The battle for Kota Bharu, in British Malaya, began shortly after midnight local time on December 8, more than an hour before the attack on Pearl Harbor started. Southeast Asia got the offensive’s main weight, three armies, yet only 11 of the army’s 51 divisions went south, with most of the rest kept in China and Manchuria.

The admiral who planned it had no confidence in a long war

Isoroku Yamamoto, commander of the Combined Fleet, opposed this war. In October 1940 he told Konoe, as an NSA history translates it: “If I am told to fight regardless of the consequences, I shall run wild considerably for the first six months or a year, but I have utterly no confidence for the second and third years.”

The plan was still his. In a letter of January 7, 1941, he outlined it to the navy minister, Koshiro Oikawa, urging Japan, in the words a National Park Service study quotes, “to decide the fate of the war on the very first day.” He threatened to resign to get it adopted, arguing, in Morton’s words, that “the success of the southward drive depended on the destruction of the American fleet.”

The carriers sailed before the Hull note arrived

On November 26, Secretary of State Cordell Hull handed Japan’s envoys a proposal, marked “Tentative and Without Commitment,” that Japan “withdraw all military, naval, air and police forces from China and from Indochina,” with the asset freezes lifted on both sides.

The strike force was already at sea. Its six carriers had left Tankan Bay in the Kurils on November 26, Tokyo time, still November 25 in Washington, under an attack order “held until the results of the diplomatic negotiations were known.” Tokyo rejected the note the next day.

Date in 1941	Step toward war
July 26	US freezes Japanese assets
August 1	US bans aviation-fuel exports, caps other oil sales
November 26, Tokyo	Carriers sail from Tankan Bay
November 26, Washington	Hull hands over his note
December 1	Imperial Conference: “Japan will open hostilities”

The sleeping giant line, which nobody can trace before 1970

At the end of the 1970 film Tora! Tora! Tora!, Yamamoto’s character says, “I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve.”

William Safire’s Political Dictionary quotes the line and adds: “The attributed remark, however, has no printed evidence to support Yamamoto’s use.” Yet a 2006 Pacific Air Forces commentary still said Yamamoto “spoke the now famous words.”

In a real letter of January 9, 1942, to the journalist Taketora Ogata, quoted in Hiroyuki Agawa’s The Reluctant Admiral, Yamamoto wrote that a military man “can scarcely pride himself on having ‘smitten a sleeping enemy’,” and that the enemy, “angered and outraged,” would “soon launch a determined counterattack.”

The attack missed the carriers and the oil tanks

In under two hours the raid sank or put out of action 8 battleships, 3 light cruisers and 3 destroyers, and killed 2,403 Americans, by Morton’s count. Every December 7, federal law asks the president to call for flags at half-staff in honor of those “who died as a result of their service at Pearl Harbor.”

But “the richest prize, the three carriers and their escort,” was not in port. The attackers also overlooked “the repair shops, the dry dock, and the oil tanks then filled to capacity.”

“Perhaps the major error of the Japanese was their decision to attack the United States when the main objective of the war was to gain the strategic resources of Southeast Asia.” - Louis Morton, Strategy and Command

Instead of a quick settlement, the attack “unified the American people as nothing else could have done.”

Japan’s declaration of war, dated December 8, blamed America and Britain for “a direct severance of economic relations, menacing gravely the existence of Our Empire.” It was issued in the name of an emperor “seated on the Throne of a line unbroken for ages eternal,” a line Japan dates to 660 BC.

It never mentions Pearl Harbor, and the order that started the squeeze never mentions oil. Strictly FYI.