And yet the Japanese did the same thing before the Pacific War, with all of those territories, when they managed to sneak past the US Coast Guard and the US Navy to smuggle arms into Vancouver and British Columbia to help support Canadian rebels. If they can do it once, they can do it again
And you don't think the situation is just slightly different post-SGW than it was in 1932?
When the Japanese did it in the 1930s it was against a U.S. that had spent the last decade under pacifistic Socialist presidents who had badly neglected the American military during their time in power. And even then the Japanese 1) still got caught, and 2) failed to set off any sort of Canadian uprising.
And post-SGW the following factors all make the Japanese trying to repeat the smuggle arms to the Canadians gambit even less likely.
1) After Operation Blackbeard the U.S. is going to be far more paranoid about being sneak attacked by its neighbors than it was in 1932, so it is very unlikely Japan will be able to catch the U.S. Navy and Coast Guard asleep at the switch a second time. The waters off the Canadian Pacific Coast are accordingly certainly going to be heavily patrolled;
2) Given the massive technological advances in radar and aircraft since the 1930s, it is now much easier for the U.S. to guard its coastline than it was in the 30s;
3) Given that the U.S. has the atomic bomb and Japan doesn't, the potential price for Japan getting caught smuggling arms into Canada is far greater than it was in the 1930s. (What does it profit a nation to smuggle a craft of rifles to Canadian rebels if it then loses Tokyo?) and;
4) Even if Japan eventually gets atomic weapons in sufficient quantity to enforce MAD on the U.S., Japan is still far more vulnerable to the U.S. smuggling arms to nationalist rebels in Japan's occupied territories than the U.S. is to Japanese smuggling. This wasn't true in the 1930s because the U.S. did not then have any bases particularly near the Japanese colonies, and given submarine technology in the 30s, U.S. subs could not realistically get deep into Japanese territory without being spotted (since submarines in the 1930s needed to spend most of their time on the surface.) By the 1960s though the U.S. will have nuclear powered submarines that can easily cross the entire Pacific while staying submerged the entire trip, so it is now much easier for the U.S. to sneak ships into Japanese waters. And of course the U.S. is very likely to acquire bases in Australia. (Which is probably terrified of the Japanese Empire.) If the U.S. is given a carrier base in Australia, they will be able to pretty much permanently plant a carrier battle group or two right off the Indonesian coast, which will make it incredibly easy for the Americans to smuggle arms into Indonesia. (And with bases in Australia, the U.S. carrier groups can also pretty easily sail into the South China Sea which will enable smuggling arms to nationalist rebels in Vietnam and the Philippines.)
So again why are the Japanese going to pursue a policy that has a very real possibility of leading to the nuclear destruction of Japan and even if that doesn't happen still 1) won't work and 2) gives the U.S. the green light to do the same thing (and far more effectively) to Japan's own colonial empire?
- especially if the US is trapped in a cold war analogue with Germany and Austria-Hungary (which seems to be the way the post-SGW world looked like it was heading).
Nothing in the novels supports that the U.S. and Germany-Austria-Hungary were moving towards a Cold War situation. If anything the novels show the exact opposite as they showed the U.S. and Germany having an excellent wartime relationship (seeing how Germany shared nuclear secrets with the U.S., something that OTL the U.S. never (intentionally) did with the Soviets) and then continuing to work together post-war.