So, are we ready for a land invasion?

All this talk of an invasion of the United States, I got to wondering how that would work. Of course, I realize that Trump’s posturing about the Central American refugees – the “caravan” – is political nonsense intended to rile up the rubes. In no sense is this an invasion.

But what if there were an invasion. What if Mexico finally got tired of being called ugly names by the American president and decided to do something about it? What if they decided that they were going to address the problem of American drug money going to Mexico’s cities and funding the drug cartels that are making so many places unlivable? In other words, what if the tanks started rolling into Texas and the Southwest? Suppose that we didn’t see the military build up along the border. Or, suppose we did.

Is the US military positioned such that it could repel a traditional land invasion? I’m imagining something akin to Barbarossa or the Germans crossing the Ardennes. I wall just isn’t going to do it. Is the only plan that if Mexico occupies San Diego, we nuke Monterrey? (I don’t know why Monterrey. Why not?)

Given that the OP starts off with political commentary, let’s move this over to Great Debates.

General Questions Moderator

I’m sure it wouldn’t be much trouble to get the Apaches, AC-130s, tanks and vast quantities of war material and whatnot into the border in position to rout the Mexican forces. After all, such U.S. forces are often deployed to the Middle East, which is a far further distance away. In fact, it’s hard to think of a war that would be more straightforward for the U.S. to fight in and win.

The Mexican tanks might push some distance in at first, if they took the U.S. by sheer surprise, but it wouldn’t be long at all before they started getting hammered by drones and other airstrikes.

The thought of that happening is so sad.

I’d be tempted to defect and help the Mexicans.

In all seriousness though, no country would be delusional enough to mount a land invasion against the US. It would be the most fail-filled 45 seconds of their lives, if they survived.

It might take a couple of days or a week, but not longer than that. We have, after all, a National Guard, and aircraft and things like that. Plus Mexico would quickly have other matters to concern them, when the Pacific fleet appears offshore and begins causing Issues.

First, we send out the Air National Guard and kill all their tanks and shoot down all their planes. Then we send over the Stealth bombers and kill their command-and-control, and all their radar. Then the B-52s go over and destroy all their planes and tanks on the ground. We would have stationed a lot of ships over the horizon, and fire missiles at Mexico and destroy all their airfields and sink all their shipping and kill their electrical grid. After that, the Mexican fortunes are likely to take a turn for the worse. The whole thing, from first invasion to rendición incondicional might take two or three weeks.

What you need to understand is, in a straight military-to-military confrontation, the US is absolutely invincible.

Mexico spends about 10B USD on its military. The US spends about 68 times as much on its military. Cite. The US GDP is about ten times that of Mexico.

It would not be pretty.


I think the hordes of crazed Canucks would make it about 30km before they realized that there were no Tim Horton’s on every street corner and retreat in panic.

To “seriously” address the OP: Any invasion from the South would either have to go through miles and miles of miles and miles, where they would be easy targets for helicopters and other aircraft, or would head into major population centers which just happen to have major military bases in/adjacent to them. 45 seconds is being generous.

Let’s not forget that Canada is an ally of Mexico, and so the US could be faced with fighting a war on two fronts. Between the brilliance of Canada’s Defence Scheme Number 1, which has been gathering dust since the 1930s, and the current US commander in chief, I rather fancy our odds.

Probably Native Americans would join in. Just suggest “Ghost Dance” and you’ll have a fifth column.

There is literally zero chance that the United States would fail to detect a buildup on our borders. Between our ability to intercept communications and our ability to detect things from space, the movement of numerous military units in a very unusual manner would be as obvious as a 500 watt lightbulb in your bedroom.

But even if they did try to mount an invasion, one could expect that within hours, rotary and fixed-wing aircraft from bases in the areas of San Diego, Tucson, El Paso, and elsewhere would be able to seriously disrupt a movement of military vehicles across the border. This is especially true given the comparatively small size of the Mexican armed forces and its rather modest capabilities. For example, Mexican armor mostly consists of armored vehicles and not really tanks as you’d think of them.

The invaders could seek to use the cover of urban areas to mitigate this risk, but – and I don’t want to overplay the Red Dawn scenario – it isn’t like armies are itching to engage in combat in cities.

There is no conceivable scenario in which the United States would use nuclear weapons in this war.

The only halfway plausible scenario I could think of in this general vein is if the Mexican military sought to do some kind of raid to achieve a very limited objective, like going in to grab someone and then getting out extremely fast, or something like that.

It doesn’t look like the Mexican Army has anything like a proper tank, nor does its Air Force have any jet fighters. This would be a disaster for Mexico.

Canada has some armor, some F-18s and experience projecting force. Could they make a lightning strike and capture Seattle or even New York? Maybe, but it wouldn’t last.

You ever tried to drive I-5 during rush hour? They wouldn’t make it past Mount Vernon.

Plus, to add insult to ludicrousness, if Mexico came up through California, the first thing they would encounter would be MC Air Station Miramar (“Top Gun”), the Pacific Fleet homebase and Camp Pendleton. So they wouldn’t just be fighting against Americans on their home turf but the elite of the elite American forces who have spent the last 60 years scoping out every inch of the battlefield and wargaming it practically every day of their lives.

And would face the possibility of immediate counterinvasion from Fort Bliss, unless they invaded Texas, in which case…Fort Bliss. It’s impossible.

What is the difference between illegal immigration and invasion?

No. Canada can’t put together a sufficiently large offensive force without being detected. The Canadian Army is spread out, lacks the immediate supply needed, and might mount one division of strength, tops.

If you can’'t tell the difference between someone looking for a better life in a rich country and an invading army, you’re not being serious.

I would think the US military units in Texas alone would be more than enough to halt any advance from Mexico, as long as other countries don’t enter the fray.

You mean like we detected, on radar, the obvious, massive buildup around 7AM on December 7, 1941?

This. We’re significantly more prepared to defend one than any country (or combination of countries) on Earth is prepared to launch one.

Yeah its not like the US military budget is a little bit bigger than Mexico’s (or any other country in Latin America, or the world). It is A LOT bigger (100x more to be exact $681Bn vs $5Bn)

US military assets may be spread over the world, but those within a day’s drive from the Mexican border still dwarf* the largest army Mexico could put together, even if they could (in secret) concentrate every last solider, vehicle, artillery piece, round of ammunition etc on the border.

  • the raw number of soldiers might not (the number of troops is only 2x or so) but that is meaningless in a modern war (as shown by the Gulf War)