[VICE]
First thing's first. How could the rest of the world disable the US nuclear capacity?
[Dylan Lehrke]
It is virtually impossible to eliminate the US nuclear arsenal since it is based on a triad of land, air, and sea delivery systems designed to provide a counterstrike capability. The submarine-launched ballistic missiles in particular are widely accepted as the most survivable element of the US nuclear deterrent as a portion of it is always at sea. The land-based missiles too are difficult to eliminate, as they are in hardened silos in the middle of the country. Any adversary facing the United States would need to either be willing to absorb a nuclear attack or develop a ballistic-missile defense system currently beyond the scope of anything technologically feasible.
[VICE]
Well, I've got a pretty good blueprint of one in my bedroom, so let's a**ume it's totally possible. If not, perhaps we need to go to the source: Obama. Could the nuclear football be grabbed from the president?
[Lehrke]
I can't really answer this one since we have very little information on the technical aspects.
[VICE]
OK. Let's just a**ume the technical aspects are that he carries it around in his pocket and I've stolen it. So, once the nuclear capabilities are down, what could an invasion of the US look like?
[Lehrke]
The US is the sole country in the world that has the capability to project force across the globe on a large scale. The combined military air- and sea-lift capability of the rest of the world would be insufficient to even get a foothold on the continental United States. The amphibious a**ault capability of the world's militaries, excluding the United States, is simply too small.
That means the adversary would have to seize and use civilian aircraft and ships not designed for nonpermissive environments. These ships would require secure bases in Canada and Mexico, since they lack the capability to deliver forces onto unimproved shores. Thus, any attempted invasion of the US would first look like a rather motley caravan of vulnerable civilian ships and aircraft.
If these forces managed to avoid US attacks and build up, they could then launch an attack over land.
[VICE]
I'm sure we could manage it. Where would an invasion begin? Which parts of the American coast are most vulnerable to attack?
[Lehrke]
As I already noted, the amphibious-a**ault capability of the combined militaries of the world are simply too insignificant to get a beachhead on a coast. If they managed to go undetected, itself an impossible feat in light of modern surveillance capability, they still could not build up a force of any size before being pushed back into the sea.
Thus, an invasion would have to come via a land border, with the terrain of the southern border (that with Mexico) being most conducive to military operations. However, the fact that the largest US Army armor base happens to be in Texas naturally would hinder such an attack. Going through the Canadian border—out West, to avoid the Great Lakes and St Lawrence Seaway—would be easier, although the invasion would then be limited to light infantry and would have trouble concentrating forces. In addition, it would fail to take over population centers or other important strategic points, since it is mostly national parks out there.
[VICE]
Well, once we have the national parks, we have the bears and wolves on our side, which will make us unbeatable. I guess the big question here is: Are the world's combined forces—including those mad North Koreans, because every little helps—enough to defeat those of the US?
[Lehrke]
Yes, but only if the US is on the offensive or only if defeat does not equate to conquer or destroy, which it generally does not. The world could, for example, certainly contain the US as the US did the Soviet Union.
But the question you are really asking, if I am correct, is: Are the world's combined forces enough to conquer the United States? Here the answer is no, for it is much harder to project force. It requires logistical resources that the rest of the world simply does not have.
OK. That's disappointing.
[Lehrke]
The primary problem here is geography. Just as the vast Russian steppe swallows armies, so would the oceans that surround the US. No matter the manpower or armament, it must be delivered across the Pacific and Atlantic in order to be brought to bear. This is where US naval and air power would destroy any adversary, far before they sullied the US shore.
And this is where you meet the second primary problem, which is technology. There are not enough aircraft carriers and amphibious warfare ships in the combined navies of the world to force an entry past the US Navy. There are not enough attack fighters to gain air superiority against the US Air Force.
This is how amazingly out of balance the military might of the world is today.
[VICE]
Could we find a work-around?
[Lehrke]
The solution for the invading world armies would be to negate the importance of geography and technology. This means not relying on armies and navies and air forces but instead targeting the US in the space and cyber domains. By defeating US satellites and attacking US networks, one bypa**es geography and eliminates technology, both that of the military and within the industrial base that is at the core of that military might.
Cool, so we'll just get the hackers onboard.
[Lehrke]
However, one still does not conquer the soil. So we arrive at the same conclusion: as the world military balance stands today, even in the unlikely case that the entire world aligns against them, the United States could not be conquered. It can only be defeated. I suspect you had hoped for a more Red Dawn-type possibility but I can't offer one without stretching reality beyond the point of reason. We would have to bring in pure science fiction to make it feasible.
[VICE]
Oh well, I guess that's pretty emphatic. Thanks for humoring me, Dylan.