>>512293787
I agree with the geographical reasoning for clearing all the way to Panama, but I am specifically leaving out Mexico and Central America for very good reasons.
Let's just say there is going to be one hell of a mess beyond comprehension there, and it will extend long after the wars 'settle down' to the point where Europa can be formed from the ashes.
The Carribean Islands will be a battlespace that can not be avoided, but Central America (especially Mexico) will be a persistant battlespace not worth the additional years of cleansing.
One of the solutions will be a GREAT AMERICAN CANAL from Gulf to Pacific just inside the Mexican border, with a concrete & guarded buffer on the Mexican embankment side. The Canal will be large enough to have a Nimitz carrier sail through it. With multiple inland reservoirs for recreation, industry, commercial, and military naval bases.