Japan's pre-emptive strike in 1941 sure worked out well.
The Japanese militarists did not believe that the U.S. would stick with the fight for the long haul. The problem with the 1941 strike was that it was too restrained. They should have invaded Hawaii, or at least Midway, and continued air strikes until all the oil handling facilities in Hawaii were destroyed.
In the event, the attack on the U.S. was optional, the Japanese could have bided their time until the U.S. went back to sleep. Japanese internal politics between the militarists and more accommodating factions, and the reckless U.S. demands forced the militarists hand. North Korea is much closer to Japan, and does constitute an existential threat. North Korean facilities are not immune from attack like those in the U.S. were in 1941. The only thing that has sustained North Korean bluster is the fear of Chinese intervention on their side. Were the Chinese military exercises a warning to the Norks, or the U.S. and Japan? I think the Chinese are being deliberately ambiguous. They want to retain North Korea as a thorn in America and Japan's side, but don't want to provoke a war that would be costly and destructive for them, nor do they want to lose their pet pit bull. They don't even bother to apologize when it occasionally kills some of their neighbors' children.