The basic premise of the original Red Dawn was ridiculous. I actually analyzed that scenario as a staff exercise once upon a time. Suffice to say that while it's just 60 air miles across the Bering straight (as Sarah Palin loved to point out) it's nearly 4000 sea miles from Vladivostok to Anchorage, those being the closest ports capable of mounting the invasion and supporting the ground operation, respectively. And then it's another 2000 miles by land to the continental US. On a two lane highway. Through the mountains. In the Arctic. As for the supposed airdrop out of Cuba, all the runways in Central America couldn't support it. The only believable part was the private arsenals to be found in Colorado high-schools.
But at least the Soviets had ships and planes that could, at least in theory, travel the required distances with division sized forces. China? No. North Korea? They can't even pave the roads at their "missile" base.
I could go on, but I won't, because I still hope to see Ronald Reagan's Nicaraguans from coming over the border at Brownsville, Texas and I don't want to discourage them. It's just two days drive! After they conquer Honduras, Guatamala, El-Salvador and Mexico of course, and assuming their 100 T-55 tanks didn't break down on their two-thousand mile Le Mans rally through jungle, mountain and desert... Communism on the Doorstep! Guess the Gipper wasn't sure 1 Cav div there in Fort Hood would be able to win that one for him.
Now that would be a film worth watching. Maybe for a sequel Grenada and Panama could tag-team?