I would take anything from the John Birch Society with a grain of salt.
I have never subscribed to the various Pearl Harbor conspiracy theories for several reasons:
1. A Pearl Harbor attack was not needed to get the US in the war. It was clear in fall of 1941 that war was coming and it would include an attack on the Phillipines. The US, despite pre-war plans to not defend the islands in force, was engaged in a major build up with three US Army Divisions moving to re-enforce them.
2. Had FDR any sort of reliable intelligence about a Pearl Harbor attack, then he could have easily arranged an ambush. While taking out Kido Butai itself would have been difficult, there are more than enough Army and Navy aircraft available to wipe out the first and second waves and cripple the IJNs main striking arm for a year or more.
3. Had any hard intelligence about Pearl Harbor being a even a probable target been known, the alert level could have been raised. Given tensions at the time it would not have been unreasonable.
4. FDR gets no personal or political benefit from knowing about the attack but letting it proceed unhindered. The traditional “FDR sacrificed some old battleships” argument doesn’t wash because in 1941 those old battleships were all we had.
The opinion piece was by Texas Congressman Martin Dies, not a JBS editorial, so the issue is Dies' credibility.
Did he suddenly make this story up in 1964, or was there some "ground truth" to it?
First, so far as I know, everything CougarGA7 said on the matter is true, so the Dies story starts off on pretty shaky ground.
And second, we might note the timing here -- April 1964 was presidential primary season during the first election where the "Solid South" began to switch from Solid Democrat to Solid Republican by voting for Senator Barry Goldwater.
Since Dies was a classically conservative Southern Democrat, his article in the John Birch Society magazine could have been an effort to express his own disappointment with the party of FDR and now LBJ.
Texas went for Goldwater in the 1964 primaries, but native-son LBJ carried the general in November.
Some counties in and near Dies' district did vote for Goldwater, and the entire state of Louisiana next door voted Goldwater.
So 1964 was a critical year for Conservative Republicans in the South, and the Dies article may have helped break the ties that bound Southerners to the old Democrat party.
But, all that acknowledged and understood, does that make Dies' alleged map showing Pearl Harbor as Japan's target just pure fiction?
GLC: " A Pearl Harbor attack was not needed to get the US in the war.
It was clear in fall of 1941 that war was coming and it would include an attack on the Phillipines."
In fact, there is reliable historical evidence showing that President Roosevelt was worried that evening of December 7, 1941, whether even the attack on Pearl Harbor would be enough to convince Congress to declare war.
It was a huge question in the minds of top US leaders just what it would take to bring the US into war.
GLC: "Had FDR any sort of reliable intelligence about a Pearl Harbor attack, then he could have easily arranged an ambush. "
There is reliable historical evidence showing that FDR specifically rejected sending out the US fleet to find the Japanese in favor of his written orders to all US commanders that Japan must be allowed to commit the first overt act of war.
GLC: "Had any hard intelligence about Pearl Harbor being a even a probable target been known, the alert level could have been raised."
War warnings were sent to all US commanders in the Pacific, but they were vague and did not mention possible air attack on Hawaii.
What they warned of instead was possible sabotage, and that explains Short's and Kimmel's actions in response.
The question is whether Washington knew enough to have more clearly warned Hawaii of the coming attack.
The alleged Dies map suggests they did, so how true was the story?
GLC: "FDR gets no personal or political benefit from knowing about the attack but letting it proceed unhindered.
The traditional “FDR sacrificed some old battleships” argument doesn’t wash because in 1941 those old battleships were all we had."
We also had aircraft carriers, and more modern cruisers which were sent safely out of harm's way, just in time.
There is no evidence -- none -- suggesting that FDR expected anything like the levels of damage inflicted on December 7.
But in reality, all but one of those old battle-wagons were soon patched up and back in the war, so it is hard to imagine how the damage could have appeared to be worse, and yet actually been relatively small.
And it was precisely the appearance which mattered most to Roosevelt politically -- that's exactly what it took to convince Congress and the American people we had to get into the war all-out.
Still, the bottom line on the Dies alleged map is that, as CougarGA7 says, we have no other evidence to confirm it, and the timing of April 1964 suggests Dies' article had an important political motivation.
But does all that make the map story a lie?