A little history on that if you like.
Claim: U.S. Intelligence had foreknowledge that the Japanese fleet was approaching America with the intent to attack and our oldest ships were left in place at Hawaii instead of moving them and preparing for the attack.
Method: Washington had complete foreknowledge of the attack on Pearl Harbor and did not warn the commanders on the ground in Hawaii, allowing it to happen.
Manipulation: The United States would end up declaring war but the American people wanted to know why we were caught offguard at Pearl Harbor so president Roosevelt appointed a commission to investigate called the Roberts Commission.
The Roberts Commission concluded that Washington faithfully executed its duty and that the fault lay with the commanders in Hawaii. The commission found the commanders of Pearl Harbor, Adm. Husband Kimmel and Gen. Walter Short, guilty of 'dereliction of duty'. The Commission presented their findings to Congress January 28, 1942.
Event: The Japanese bombed Pearl Harbor on December 7, 1941 and killed 2,403 people. Washington knew of an impending attack but somehow was unable to prepare for it which resulted in the U.S. entering the war. Once again, the deaths of Americans caused sufficient outrage and panic to cause the American people to support the war. Same as with the Lusitania in WWI.
Result: Commanders Kimmel and Short received hate mail and thousands of death threats as a result of Washington's claim that they did not prepare for the Japanese attack on Pearl Harbor and that it caused the death of innocent Americans. Kimmel and Short protested the Robert's Commission findings because Robert's ran the hearing where evidence was introduced but not recorded, there were statements made not under oath, and Kimmel and Short were denied the right to question witnesses. In August of 1944 a Congressional Resolution mandated the trials of Kimmel and Short.
At the proceedings, the attorneys working for Kimmel and Short provided proof that Washington had complete foreknowledge of the events at Pearl Harbor and withheld this information from the commanders in Hawaii. Later in 1946 while giving Congressional testimony, Admiral Kimmel stated;
"We needed one thing which our own resources did not make available to us. That vital need was the information available in Washington from the intercepted dispatches which told when and where Japan would strike. It is my conviction that action from the Navy Dept. at any one of these significant dates in furnishing me with the information from the intercepted messages would have altered the events of Dec. 7, 1941."
Based on the evidence introduced by Kimmel and Short, the Navy board overseeing the trial was outraged and they exonerated Kimmel and Short, laying the blame squarely on Washington D.C. The Army Pearl Harbor board concluded Washington had full foreknowledge of the attack and concluded with these words.
"Up to the morning of December 7, 1941, everything the Japanese were planning to do was known to the United States."
The people of the United States did not learn of these verdicts because president Roosevelt ordered the results to be made confidential.
