Just wondering if that upset him that they accelerated an enemy into the mix. When he was most likely uninterested in the United States at the moment.
u/kieslowskifan answered a different question but covered Hitler's thinking on declaring war against the US.
Although an expansion of the war carried with it new uncertainties, a number of German military planners mistakenly concluded that Japan's entry into the was in the Pacific was largely beneficial to Germany's strategic interests.
As a follow-up on this one: did Hitler ever seriously consider not declaring war on the US after the Japanese attack? And, hypothetically, would the US have considered declaring war against Nazi-Germany if they hadn't first?
According to Ian W Toll's Pacific war trilogy, Hitler was ecstatic.
"At last, we have an ally that has not been defeated in 3000 years." Hitler seemed to believe that Japan would tie down the U.S. for years, and draw resources away from Britain and the Soviet Union.