I think you could definitely make the argument that this revelation influenced Hitler’s decision to declare war on the 11th. I think that if Hitler had decided to pass on declaring war on the U.S. like Japan did on the USSR then Roosevelt would have been in quite a tough position.
Now clearly as abb pointed out, the Tribune if very anti-Roosevelt and jumped on the chance to break this incredible story. I believe had the Japanese attack on Pearl Harbor not intervened this story may have grown into a full blown scandal for the President. Pearl Harbor made the whole point mute though and the story quickly died. I did a report back during my masters degree research in which I looked at who it might have been that leaked these war plans. We know that Senator Wheeler gave these plans to the Trib, but what is not know is where he got them from.
Wheeler claims that he got them from an army captain, but that’s where the trail goes cold. One hypothesis I presented is that it might be possible that F.D.R. himself allowed the plans to leak. With war with Japan appearing more and more a forgone conclusion this may have been a means for F.D.R. to draw Germany in as well by making public his intent to destroy the Nazi’s first even if Japan gets involved in the war. F.D.R. is Machiavellian enough to make a move like this and it would be an example of realpolitik that is reminiscent with other moves he did make throughout his presidency.
Now my conclusion is that this is not the most likely scenario as to the source of the leak, but it is an interesting one none the less.
You could be right. War with Japan became almost inevitable when they occupied French Indo-China. It was simply a question of when. And it would be a way to goad Hitler.
On the other hand the US was really hoping to postpone the war for as long as it could, because we were not ready. Which means had Japan not moved when it did, this story would have hurt FDR for several months with people who leaned isolationist. Which could adversely effect defense bills.
Some point to this leak as evidence that FDR knew of the Pearl Harbor attack beforehand. Not the only evidence, just one element.