Pearl Harbor

Because it knocked out most of the American Pacific fleet at the time, thus allowing the Japanese -TIME- to expand into the Pacific without having to worry about US naval reaction.

Remember, they also knocked out the British fleet in the Pacific at the same time they were doing Pearl Harbor.

The Japanese however failed because of the fact that the US carriers were NOT at the time present at Pearl Harbor during the attack. If this would've happened, the Japanese would've have had serveral more months of movement in the Pacific.

Why?

Because at the time, it took LOTS OF MONTHS to build a new ship.

it may not be the most important part in world war two, but the Japanese bombing pearl harbour influenced America to join the war, a great ally to England, Russia and all te other country against the Nazis

first answer:

The ONLY US Navy ships that were not at Pearl Harbor, were the ones that mattered! The US Aircraft Carriers. Had those carriers been present during the attack; history would have been DRASTICALLY ALTERED!

second more correct answer:

A large part of the US Pacific Fleet was not at Pearl Harbor on the morning that it was attacked.

All three Fleet Aircraft Carriers in the Pacific were not at Pearl Harbor.

One of the nine Battleships in the Pacific was not at Pearl Harbor.

Eleven of the 13 Heavy Cruisers in the Pacific were not at Pearl Harbor.

Five of the 11 Light Cruisers in the Pacific were not at Pearl Harbor.

37 of the 68 Destroyers in the Pacific were not at Pearl Harbor.

47 of the 51 Submarines in the Pacific were not at Pearl Harbor.

The ships that were at sea, were primarily involved in operations to reinforce Midway & WakeIslands, escort convoys to/from the Philippines, or were on patrol in waters not far from Hawaii.

Yes, the USS Ward sunk a Japanese midget sub trying to enter port at 6:45am. Naval command disregarded the warning, and the aerial attack started at 8am. Also FDR sent a warning to be on the look out for an attack which was imminent.

There are two ways to look at this question: (1) was it possible to prevent Japan from attacking the US in 1941/1942, or (2) was the attack on Pearl Harbor on December 7th preventable once the Japanese had decided to carry it out?

To answer the first, which, really, boils down to "could a US-Japanse war be prevented", we must look at what reasons there were behind the US-Japanese antagonism in the 1930s and 1940s. In that time, both the US and Japan were Imperial powers - both had significant colonies and dependencies outside their national homelands, and both were major international powers. The Japanese were, in fact, the premiere power in the Eastern Pacific, a fact that the rest of the world (primarily Western nations) preferred to downplay and marginalize. This led to a long series of "slights" (as the Japanese saw them) where Western powers banded together to deny the Japanese soils which they themselves would benefit from. In particular, the Japanese saw the continued existence of the Dutch, British, and French Empires' colonies in their area as encroachment on "their" (the Japanese's) sphere. Put it in perspective, it would have been the same as if Japan owned Gibraltar, Luxembourg, and Ireland.

All this is a bit academic - the root of the conflict is pure power imperialism. The Japanese wanted to expand their sphere of influence in East Asia, and the United States (in conjunction with Britain and The Netherlands) were determined to protect their own colonial possessions and counter the increasing Japanese influence. This imperial conflict resulted in a myriad of contentious flashpoints: the Western support of the Chinese during the 2nd Sino-Japanese War (1937-45), the eventual blockage and embargo of many critical raw materials (oil, rubber, aluminum and several others) from Western countries to Japan, and fierce military buildups/shows of force on all sides.

The answer thus has to be "No, a US-Japan war could NOT have been prevented." Given the aggressive nature of Japanese imperialism, and the refusal of the Western nations to make concessions in the face of that imperialism, a military conflict was inevitable. Indeed, the fact that a war was raging in Europe made the military conflict much more likely, as Japan (rightfully) judged that the European Allies would be too distracted and weak to defend against a military action by the Japanese in Asia.

As to the second question, "Could the Dec 7th attack on Pearl Harbor been prevented once the Japanese decided to attack", this hinges on two ideas: firstly, that the United States could have detected the attack force (or at least, discovered the decision to attack) ahead of time, and secondly, that there would have been some meaningful action the US could have taken to stop or discourage that attack.

It is highly unlikely that the US could have predicted the exact nature of the Pearl Harbor attack. While US Intelligence was quite good at intercepting Japanese Naval and Diplomatic messages (and decoding them), the historical record shows that the US was unsure of what form hostility would take, and certainly had no inkling of an exact (or even approximate) date that such hostilities would commence. US military estimates were that a possible Japanese attack could happen at one of several places: the Philippines (judged the most likely), Port Moresby, the Panama Canal, Pearl Harbor, and the US West Coast (San Diego or San Francisco). There was significant preparations at each of those places, but, being peacetime, there was a severe limit as to what those preparations could do. None of these preparations were useful, however, as the Japanese has sufficient spying in place at each of them to report back such preparations and counter them.

The Japanese attack force itself intentionally sailed a course which was far away from normal shipping or flying channels (and, being well before the days of satellite recon), the odds of some ship or plane seeing them was remote, and communicating that fact back was even smaller. Historically, then, there's absolutely no reason to assume that the US could have detected the Japanese attack force before they reached the launch point north of Oahu.

As to the possibility that the US could have done something about the attack force before it launched on Oahu, the idea is ludicrous. Militarily, the US Pacific Fleet was substantially inferior to the Imperial Japanese Navy, and any attempt to force a fleet action north of Oahu would have resulted in the permanent loss of most of the US Navy, including the valuable carriers. Let's be clear about this: instead of having 6 battleships crippled and 2 lost (plus a couple of cruisers and destroyers) and 200+ planes destroyed, a US Navy vs IJN battle north of Oahu would almost certainly have resulted in a loss of 3 carriers, ALL the battleships, 400+ aircraft, and numerous cruisers and destroyers, in exchange for probably losses of 1-2 IJN carriers and maybe a battleship. Politically, discovery of the IJN attack force significantly ahead of time could have forced the Japanese to cancel the attack, but that possibility ended about Dec 5th or so.

Thus, the answer to the second question is also "Preventing the Japanese military attack would have been solely a stroke of highly unlikely luck. No reasonable action of the US could have prevented it."

Now, there were a large number of things that could have been done in early December by the forces at Pearl Harbor to more effectively defend the installation, and both reduce the losses and inflict more casualties on the attackers, but that is beyond the scope of this question.

Japan also attacked Guam, The East Indies, Malay & The Phillipines as well as Pearl Harbor On the day of November 7, 1941,exactly one month prior to the Pearl Harbor Attack that still "...live(s) in infamy!", according to FDR, Japan issued The Combined Fleet Order No. 1 to its military forces. That order laid out the plans for the Japanese Empire's boldly extensive South Pacific operation. As far back as March 1, 1941, they planned to send the 1st Air Fleet to attack Pearl Harbor,the 2nd Fleet to attack the islands in the East Indies, Malay, & The Philippines and the 4th Fleet to attack the Island of Guam. Japan's plan was for its Southern Force to invade Malaya while its Philippine Force invaded and occupied The Philippines. A Northern Force would lay back to guard the eastern home waters of Japan while the main naval body was positioned in Japan's Inland Sea home waters.

Many Reasons

• Japan chose Pearl Harbor for many reasons. *First off, Pearl Harbor was located right in the middle of the Pacific Ocean. It was "in the way",so to speak, of the Japanese expansion policy.
• Second, Pearl Harbor was where America's Pacific Fleet was located. If Japan was to wage war with America, it needed to completely wipe out all of America's power in the Pacific with one surprise attack.
• However, the attack on Pearl Harbor did not wipe out America's presense in the Pacific because the aircraft carriers, the heart of the fleet, were out at sea on training manuevers.

Japan saw the US as the only country with enough naval strength in the Pacific to be a significant threat to their expansionist plans to occupy the Pacific islands. They had discovered that the US usually kept the majority of its Pacific Naval forces (both ships and aircraft) at Pearl Harbor when not in active service. The Japanese decided to take a gamble and try to completely cripple the US Navy by attacking Pearl Harbor, if the majority of the Navy's equipment could be destroyed then the US might give up easily and permit Japan to take whatever it wanted with no resistance.

However what the Japanese could not know and was lucky for the US was that all of the aircraft carriers were out that day on a training mission. So although the attack did destroy or disable nearly everything at Pearl Harbor, those aircraft carriers were THE THING that enabled the US to fight back in the Pacific for about the first two years of the war until more ships could be built. This forced dependence on aircraft carriers also made significant changes in US Naval tactics that eventually led to the modern Navy's usage of nuclear aircraft carriers and the abandonment of the battleship and other "gunboat" type ships.

Vice Admiral Chuichi Nagumo canceled a third wave of bombers, refused to seek out the aircraft carriers, and turned back home because he feared an American Counterstrike. Because of this, the U.S. battle fleet was knocked out of commission for nearly six months but it survived.

So the answer is, The Aircraft Carriers.

There were 4 men who served as Prime Minister of Japan during World War 2:

Hideki Tojo was the Japanese Prime Minister for the majority of the war serving from from the beginning of the war to 22 July 1944.

He was replaced by a number of other Prime Ministers all serving for only short periods of time until the wars end including Kuniaki Koiso who succeeded Hideki Tojo and served till 7 April 1945.

He was in turn succeeded by Kantarō Suzuki who was in office for around 4 months until 17 August 1945 when he was succeeded by Prince Naruhiko Higashikuni who was Prime Minister until (and after) the cessation of hostilities marking the end of World War 2.
Hideki Tojo