Could the US prevented the attack on Pearl harbor?

Answer 1

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.

Answer 2

If you've seen the movie Pearl Harbor or have studied it to an extent, you will know that the US saw an enormous incoming of planes on their radar, but they thought little of it and were expecting some supplies to be on their way to Pearl Harbor anyway. If they had taken more note of it, and noticed that there were so many planes that they couldn't have just been shipping some materials over, they could have been more alert and could have probably stopped the Japanese from destroying all the things that they did. Quick summary of that paragraph in a sentence: If the US had taken note and had been more aware of all the planes on their radar, they could have done something and could have gotten some planes up in the air to fight back, rather than let the enemy sneak up on them like they did; because they were surprise attacked, they couldn't get that many planes in the air to fight back! FROM COOLIO! (Chris)

Answer 3

one way that America could have prevented the attack on pearl harbor was to not create the treaty of Washington which stated that there was a control on ships in a naval fleet and kept Japan on a 5:2 ratio. another way could have been to aqnoledge japan when wanted to be

Answer 4

There is speculation the President Roosevelt knew about the attack on Pearl Harbor before it took place. The reasoning may be that he felt war would be the one way to pull the US out of the Depression. The act was horrible but the way the country pulled together and the jobs that were created did do wonders for the economy of tghe country.

Answer 5

At the time there was a belief to keep our ships and planes bunched together to make them easier to protect. It made them easier to damage during an air attack. So spreading them out would have helped. Prior to the attacks the Admiral had performed ship inspections. Part of the protocol for inspections involved the removal or locking of arms and ammunition. Had that not been the case they could have fired back earlier during the attack. (some information provided in Walter Lord's "Day of Infamy")

Answer 6

A combat air patrol (CAP) would've warned of approaching aircraft.

Answer 7

A CAP (Combat Air Patrol) could have prevented it. But not being at war at the time, CAP's aren't used.

Answer 8

If the allies (USA), had taken the warning from a radar operator seriously the attack could have been avoided or been not so serious.