Just following up with you on this. Hastings gets this reference from a memoir written by then U.S. Ambassador to Britain from the U.S., John G. Winant. The title of the memoir is “A Letter from Grosvenor Square.”
Just to put it all in better context I will put the passage from Hastings down. The notes I post can be a little rough since they are just a transcription of notes I take when I read that I put into a program I wrote that makes them searchable. They are a bit raw since they are really designed to direct me to a page in a book for when I’m doing research (I got tired of saying, “Which book did I read that in?”)
From Hastings:
On Sunday, December 7, Churchill learned that Roosevelt proposed to announce in three days’ time that he would regard an attack on British or Dutch possessions in the Far East as an attack on America. That day at lunch, U.S. ambassador “Gil” Winant was among the guests at Chequers. Churchill asserted vigorously that if the Japanese attacked the United States, Britain would declare war on Japan. Winant said he understood that, for the prime minister had declared it publicly. Then Churchill demanded: “If they declare war on us, will you declare war on them?” Winant responded: “I can’t anser that, Prime Minister. Only the Congress has the right to declare war under the United States constitution.” - Winston’s War, p. 180.
Hastings’ recount of the conversation between Winant and Churchill doesn’t exactly support his contention that FDR would make the pledge. I do recognize that Hastings is usually pretty reliable (I have his book “Armageddon”).
I don’t doubt that FDR wanted to make this declaration, and he may have felt that he had or would have the support from Congress to make it. I think the “three days’ time” comment, coupled with Winant’s acknowledgment that only Congress could declare war was Winant’s way of saying FDR intended to drum up support for the declaration and make sure Congress would support it.
This seems to be a very important piece of the complex international situation and despite the fact that I’ve studied WW2 for about 40 years, I don’t recall having seen it before. Maybe I just glossed over it since Pearl Harbor and the invasion of Malaya made it a moot point.
Even though much of what FDR did economically was not supported by the Constitution, he did recognize Constitutional protocols, unlike our current president.