Since when did Hitler care about treaty obligations?
When they were ones he himself was pushing
Since when did Hitler care about treaty obligations?
The Japanese were not going to get "slaughtered" with an hours notice, or with three or eight or twenty-four. Enough notice for Pearl to be fully alerted and the Kido Butai simple sails away without attacking. Nagumo's orders were specific on that point.
A warning that lets the U.S. get water-tight integrity set and some of the fighters up is the best you can hope for. That makes the attack more of a push. Worst case is the fleet sorties as it brings up steam and the heavies get picked off by some of the TWENTY-EIGHT I Boats in the waters off Oahu waiting for exactly that opportunity or by aircraft from Nagumo's carriers.
Regardless of what the Japanese do at Pearl, they have also invaded Guam, the Philippines, attacked Wake and Midway, and are killing American troops. Even if the Japanese stand pat and don't move a muscle the U.S. will be at war with Germany within six months.
The KM had already sunk the Ruben James, and a U-boat (U-203) had done its very best to attack USS Texas while on Neutrality Patrol during 1941. If that boat had been a bit luckier the U.S. and Germany would have been at war in a week.
War will still happen. Hitler had an obligation under the Tripartite Pact to declare war on America anyways. Besides, the Japanese will still attack the British, who will pressure the US to join--so an American declaration of war in 1941 is inevitable.
Since when did Hitler care about treaty obligations?