Yes. Y’all come back…

Okay, okay, I’ll explain. It’s in the US’ best interest not to allow its enemies to have significant inroads on the American continent.

You need that explained, too? Didn’t they teach you kids anything in college?

The reason the US has rarely been invaded is its geography. To get to us you have to either cross an ocean or take over Canada or Mexico first. None of that has ever been easy but in modern times it means we’ll see you coming a long way off.

Mexico and most of Central and South America have fairly cordial relations with the US. Like any neighborhood, there are occasional spats and crazy neighbors, but on the whole, we get along most of the time with our southern neighbors. We also trade with them and provide aid. There are perks to being friends with the US.

Those perks are strong incentives to not let hostile powers build military bases on their lawns. Ticking off your gravy train is rarely a good plan. The US also provides military protection – as long as you aren’t picking fights with each other or other US allies.

Now, a cute little air base on an equatorial island somewhere off the coast of South America isn’t much of a threat to the US. Actually, it’s no threat at all on its own. The problem is that it will bring friends. As bases creep northwards, the threat increases. No one base is a danger but that big one in Brazil can stockpile the materiel needed to supply a whole string of more northern bases.

Left alone, a hostile power gains a foothold close enough to threaten the continental US itself. Not in a year or even a decade but over time the insignificant becomes dangerous.

Huge threat? No. But it’s also not the only one. As neighbor states find it easier to do business with a hostile power, the US loses its influence. Again, the process is slow but with enough time and money – it takes effort to pull this off – a hostile power can turn our neighbors against us. Now it’s a string of nation-states and not just airbases that can work together to threaten the US.

Of course, espionage becomes more of a thing as hostile nations move into the neighborhood. Agitating political rivalries throughout the region can also fast become an enormous headache for the US. Trillions spent over decades go quickly down the drain as our neighbors become our enemies.

That won’t make the US vulnerable to invasion. Mexico is way too underdeveloped to provide the needed land corridor. But it’s not necessary to invade to inflict harm. You think the defense budget is insane now, wait until the Air Force and Coast Guard are routinely interdicting hostile fighter jets.

Those jets and their weapons that protect the US ain’t cheap. To be sure to protect something as big as the US you need a LOT of available and capable airframes. Those planes have days of downtime maintenance for every hour of flight time. Guess who’s gonna need a lot more planes?

Or we can continue to provide our southern neighbors with aid, make it clear we don’t tolerate threats, trade freely, provide sensible loans if necessary and be the good neighbor from the north. All that comes at a cost, sure, but the price is a fraction of what we, our kids and our grandkids will pay if we ever allow the Monroe Doctrine to expire.

Basically, we are good neighbors because its the right thing to do and because it protects our backside.

Now, go get some eggnog or something.