Technically has changed a lot in 77 years.
This thread has me wondering: Conventional-warfare only (pretending nukes don’t exist,) is the United States pretty much the most un-invadable country on Earth? The only other nation that might come close is Russia, and even then just because of sheer size and remoteness of much of it.
We’re screwed. And we can’t flee to Canada!
Australia would be nigh-on impossible to successfully invade. No country has that kind of amphib capability, by several orders of magnitude.
The USMC could conquer Australia with moderate difficulty at best.
If the attack was preceded by some kind of computer virus bombing of American communications infrastructure and the power grid, possibly the invasion would fail less quickly.
The point being that there is little value in trying to go toe-to-toe with the American military. The best approach, such as it is, would be to significantly weaken the American communications and power infrastructure before starting. I suppose a campaign of terrorism beforehand designed to turn the Americans against each other would be a big help, followed by some strategic electromagnetic-pulse attacks and blacking out a few major cities.
Of course, it’ll end badly. A potential invader would be better off exploiting internal divisions to get the United States to break itself apart, then see about gently annexing some of the chunks.
We have enough military forces to defeat any likely invasion.
We only share a border with two countries; Canada and Mexico. And we have more troops stationed in America than either of those countries have available to use against us.
Other countries would have to launch an amphibious invasion against America. And our naval superiority is so far above any other country in the world, it would be no contest. The United States Navy could probably defeat all of the other navies in the world combined.
What is different than WWII?
I know that Australia had a lot of troops fighting in Africa and the Mid East, and I don’t know how many American troops were in Australia to replace them.
Japan never had the capability or the sheer number of soldiers to even remotely occupy anything other than a sliver of the North Australia coast. The fear in WW2 was that they would establish air bases on said coast, making the staging of Allied forces against the South Pacific much more difficult/costly. Note that this was with a fully mobilized military, with some small experience in amphib operations. Today…no one comes close.
No, I mean like how the Zimmermann Telegram came to light in 1917.
Do you history much?
Dad was stationed there, and told me there were plans to evacuate half of Australia. Undoubtedly exaggerated talk in the army. Thanks.
A hypothetical invasion of the US from Mexico might be the dumbest - and shortest - adventure in military history. Just a quick glance at the map reveals that Texas hosts places like Fort Hood and Fort Bliss, where a significant chunk of our heavy armor is situated. This is in addition to perhaps a dozen smaller garrisons, depots, air bases, and so on. Texas already has multiple BCTs, all the infrastructure necessary to receive reinforcement, and vast amounts of open terrain that favors US weapon systems. I’m struggling to think of a dumber place to attack.
Just remember, back then “half of Australia” would be a few towns on the North Coast. Even now, 3/4 of the country is nothing but miles and miles of nothing. The Aussies were planning on just flying everything into the bush, setting up airfields wherever there was flat, and fighting back with everything they had. Which was not much, since they’d been at war for a few years by that time and everybody was in Africa or such.
But really, the Japanese Army had very little chance of pulling such an invasion off in the first place.
Thanks, Silenus.
Straight up Baja into Camp Pendleton and Naval Base San Diego, home base of 2 carriers, 8 cruisers, 14 destroyers, 14 amphibious assault ships, and a butt-load of pissed-off Marines? 
nm
I started joking about heavy armor and taco trucks but then got wondering about how much of a land invasion could really be mustered against us. You can’t really get vehicles through Panama, so we’re restricted to North and Central America. Or shall we pretend, for the purposes of the scenario, that the invasion forces magically appear outside our land borders?
I suspect the result would be akin to the Iraqi “Highway of Death” back in 1991.
Does anyone think the US capabilities have decreased since 1991?
News reports of the day said pilots were crying after killing so many people, some of who were apparently hostages of some sort.
Like others have said, there are a lot of US Army forces stationed in Texas (2 divisions of active duty, 1 of National Guard, plus independent units), as well as the 1st MEF at Camp Pendleton, CA (1st Marine Division, 3rd Marine Air Wing, 1st Marine Logistics Group).
There are also multiple active air bases - Luke AFB, Davis-Monthan AFB, MCAS Yuma, MCAS Miramar, NAS Lemoore, Cannon AFB, Holloman AFB, Kirtland AFB.
The big question would be what the goals for any land invasion would be? If it’s not from Mexico or Canada, they’re going to have to fend off the US Navy to get here and keep the invasion going, and if it is from Mexico, there are pretty powerful US forces sitting astride the fairly obvious and useful invasion routes.
In other words, where are you going to go/what are you trying to accomplish if you were to send armored forces north through New Mexico or Arizona? It’s terrible country for armored warfare, and there’s not that much in the way of strategic things to control out there either. About all I can think of would be severing the east-west railways and roads.