By the time this memo found its way into the hands of U.S. Secretary of State Cordell Hull at 2:20 PM eastern time on December 7, 1941, it had become pretty clear that Japan and America's dog days of diplomacy were behind them.

Because like…Pearl Harbor had already been under attack for over an hour by then. The U.S. had kind of already figured out that Japan was up to something malevolent.

That ship had sailed. (Pun intended.)

But even so, it's always good to know what the enemy is thinking while they're bombing up the joint, and this memorandum gives us quite a bit of insight into Japan's frame of mind at the time.

The gist of it is that Japan felt there was nothing more to be gained by continuing friendly conversations with the United States (which was, again, kind of made clear by the whole attack-on-Pearl-Harbor thing). But the specifics listed here paint a very detailed picture of Japan's needs, wants, and feelings.

Of course, by the time President Roosevelt got his mitts on the memo, he probably wasn't all that concerned with what Japan needed from its relationship with America. Probably, he was ready to throw that memo into the Oval Office fireplace and light the Duraflame.

Part declaration of war, part Dear John letter, this memo has it all.

The only thing it lacked was an on-time delivery.