I don’t care if Japan lands in Alaska / West Canada.
Let them.
They didn’t land on the Asian coast, which is plenty good enough for me.
(edit)
Oh yeah . . . I never set up W Can/E Can. US1, I usually go 3 trans 3 tank 1 inf or 1 AC 2 trans 2 tank, and US2 move to Algeria while building 2 trns 2 tnk 2 inf (plus assorted). It has to be done RIGHT AWAY before Germany starts partying down from Anglo-Egypt. Once Germany sees 4 inf 4 tank in Africa (2 inf 2 tank from UK), Germany knows that any tanks that go to Africa will probably die in Africa, so Germany has to start making tough decisions. The first two waves of US builds march through Africa so US2 to Libya, US3 to Anglo-Egypt, US4 to Trans-Jordan, US6 to Persia. In the meantime, Japan will have probably stalled against India for a couple turns because of Pearl Harbor, so India falls on J3 at earliest, then J4 Persia. But if Russia managed to stall Japan’s advance at ALL on the India front, US, UK, and Russia can unite at Persia to block the Japs out . . . at which time they head to Africa. But the block isn’t possible if you delay the US1 build or usually even the US2 build because Germany counters the US holdings unless US reinforcements keep arriving.