Because since the Nazis already control mass media and have their secret police infiltrating most civil organizations and the military, so the Germans will need a bit of a nudge, maybe a dozen kilotons or so, to go in the right direction.
TBH the best we can hope for is mass Finlandization in the 1945 timeline, by this point we were actually contributing troops and were occupied by the USSR, and there is a saying that wherever a russian/soviet boot steps in it doesn't really step back.
If anything, the blowback after WWII was less than that after WWI, and we actually gained territory btw, and the Soviets were fine with that, and there was a sizable pro-Russian section of the population as well as a decent number of homegrown commies.
The interwar and pre-war periods were far from kind to us, so that was only to be expected.
Frankly I would have preferred if my country had stayed fully neutral in both World Wars, given our geography, though, that is nearly impossible.
In WW1 you should attack Turkey and become one of winners.And get Constantinopole.
In WW2 - soviets would take you anyway,but till 1944 you could remain mostly neutral and prepare few lines of fortyfications to slow them.And dyvision of volunteers changed per few month,so uour entire army would knew how to fight soviets.
Maybe you get Finland status then.But soviets would probably take Constatntnopole from you.