SOME (REFERENCED) WARNINGS OF PEARL hARBOR ATTACK

In the 1920's, Americans crytographers cracked several Japanese secret codes revealing war preparations. In 1940, cryptographers broke Japan's diplomatic code, learning much more about Japanese threats. (http://www.pearlharborchild.com/PearlHarbor-Dec7-02.asp: "phchild")
On December 7, 1941, at 6:30a.m., a Japanese submarine was sighted and sunk about a mile outside Pearl Harbor by the USS Ward. A message was sent, reporting that an enemy vessel had been sunk just outside Pearl, but no one was concerned enough to sound a general alarm.
In Sept., 1940, in reaction the Japanese forces taking over northern French Indochina (for much needed oil resources), the U. S. government instituted an embargo on the Japanese government, prohibiting other nations from exporting steel, scrap iron and aviation fuel to Japan. This severe action -- particularly as to fuel -- should have warned the U. S. that Japan would not take this lightly. (http://www.pearlharbor.org/history-of-pearl-harbor.asp : "hoph")
In April, 1941, Japan signed a neutrality treaty with the Soviet Union (alreeady Invanded by German forces), protecting "the Japanese back" in case of launching offensive action "in front" -- exactly the sort of action which had preceded other warlike actions of nations in the past. (hoph)
Reacting to Japanese forces moving, in June-July, 1941, from their occupied zone in northern French Indochina to occupy southern French Indochina, the governments of the U. S., Britain, and Netherlands froze Japanese monetary assets in their countries to prevent purchase of oil. hoping to render powerless the Japanese army, navy, and air force. (hoph)
Toward end of 1941, when the Soviets seemed on brink of German take-over, the U. S. demanded Japanese withdrawal from French Indochina. But "pacifist" sentiment of American public weakened aspect of this threat, motivating the Japanese leaders to believe that the American public would accept almost any offense apart from direct invasion of American continent. The only concern seemed to be the U. S. pacific fleet, based Pearl Harbor, Hawaii, which needed "nullification". (hoph)
On December 6, 1941, cryptographers gave President Franklin Roosevelt an intercepted and decoded message which ordered the Japanese Embassy to burn code books; Rossevelt commented, "This means war." But he apparently ignored the warning. (phchild)
Radar technology had progressed in Britain. (The "Battle of Britain" -- which withstood massive bombing of British cities by German planes in preparation of planned invasion -- was said to have been won by the British due to the R.A.F. fliers, radar warnings, and mathematical assessment about best deployment of forces.) But radar technology was undeveloped in U.S.
About half an hour later, on the northern tip of Oahu, a radar station picked up a huge blip on its screen, indicating a large flight of planes about 100 miles to the north. The planes were erroneously assumed to be a group of American B-17 bombers that were due in from California, even though these planes would be coming from the east, not the north. No one bothered to fully check it out. In any event, the radar signal was ignored. (phchild)
There wer early warnings: On Nov. 24 and Nov. 27, 1941, Admiral Harold Stark, Chief of Naval Operations in Washington, D.C., sent these messages, respectively, to Admiral Kimmel and Lt. General Short.
"Nov. 24, 1941...Chance of favorable outcome of nogotiations with Japan very doubtful....This situation, coupled with statements of Japanese government and movements [of, sic] their naval and military forces indicate in our opinion that a surprise aggressive movement in any direction including attack on Phillipines or Guam is a possibility."
"Nov. 27, 1941...This dispatch is to be considered a war warning....Nogotiations with Japan looking toward stabbilization of conditions in the Pacific have ceased and an aggressive move by Japan is expected within the next few days...Execute appropriate defensive deployment, preparatory to carrying out the task assigned in WPL 46 [the Naval war plan]."