What would it take to defend America?
The U.S. military is big; far larger than any other country. Larger in fact than the next 10 biggest militaries combined. Furthermore, most of the next ten biggest militaries are allied with the U.S. or have U.S. military bases within their borders. There are only two countries which present any remotely plausible threat to the U.S.: China and Russia.
A global thermonuclear exchange with Russia would result in mutually assured destruction. Adding or removing a few gigatons from any of the world’s superpowers would do nothing to change that fact. Thus, if WW3 went nuclear, no amount of either military spending or reduction thereof would make any difference and so analysis of such an event is not worthwhile.
Interestingly, while Russia has comparable nuclear capacity to the U.S., no other power comes even close. I think it is safe to say given that fact that China would never offensively use nuclear weapons since they would come off much worse from any such exchange. “I’m not saying we wouldn’t get our hair mussed. But I do say no more than ten to twenty million killed, tops. Depending on the breaks”, as Buck Turgidson so aptly said. Countries probably only need to possess the ability to accurately land a dozen warheads to effectively deter any nuclear attack.
It seems to me that France and Britain’s nuclear capacity is about sufficient: a few ICBMs, a few nuclear armed subs, and a squadron of long range bombers. Given the extremely good stealth capacity and accuracy of U.S. bombers, only a tiny arsenal would be necessary to effectively deter anyone from nuking us first. You don’t need to be able to exterminate everyone in the country, just the selectorate to effectively deter attacks. In totalitarian dictatorships you can ignore population centers and just focus on governmental targets. Furthermore, unilateral disarmament to non-Russian levels would probably encourage the Russians to reduce their own stockpiles.
Russia’s population is less than half the U.S.’s and falling. Given their outdated military hardware, Russia does not have any capacity to project force into the U.S. without the support of nukes. China, on the other hand, has approximately four times the population of the U.S. While they are far poorer and have mostly outdated military equipment, they are modernizing rapidly. But China’s total fertility rate is only 1.18 according to the 2010 Census, and their unbalanced male to female ratio and one child policies mean that time is not on their side if their leaders have aspirations for WW2esque mass warfare. The one child has ensured that for each child, there are 6 parents and grandparents placing their hopes and dreams for the future on that child’s shoulders. Any politician who seeks a war of mass slaughter will not be popular.
Another major factor which reduces the likelihood of a Chinese invasion is the Pacific Ocean. Most Americans know little about this obscure geographic feature, but there are 3,000 miles of water between the U.S. and China which would make any amphibious assault extremely difficult. Furthermore, the U.S. has the largest and most advanced navy in the world. The odds of getting a troop transport across the Pacific against the U.S. Navy’s wishes are basically zero. Even if the Navy were half or a third the size of their current force, they could easily dispatch the navies of any country who might threaten the U.S.
The biggest military threat to the U.S. is not any current military, or even any theoretical military in the next 30 years. The biggest military threat to the U.S. is economic. The only way the U.S. could be conquered by a hostile invader is if our economy first collapsed and we couldn’t afford to pay our soldiers or maintain anywhere close to our current military hardware. Therefore, temporary military spending far in excess of what America can actually afford is counterproductive to the cause of “defense” when you take a long run perspective.
True, with a much smaller military the U.S. could not project power to nearly the degree by which it currently does. For me, this is a small deal. I’m not a fan of nation building or imperialism. The majority of engagements the U.S. has gotten into since WW2 have been mistakes. You could make the case for Korea and Bosnia, perhaps. Projecting power is useful when there is some insane dictator hell-bent on world domination, or to prevent a genocide. Other than that, isolationism is a pretty good idea.
The U.S. military could be reduced to the size of Russia’s military + China’s military. That would ensure that any arms build up would be reasonably thwarted, yet we wouldn’t break the bank. I don’t personally think either Russia or China will attack the U.S. in my lifetime, but the only threat in proportion to the U.S.’s current military spending has to include aliens, and that’s just insane. At least by limiting our spending to terrestrial threats, we could keep military spending from crippling the country with debt.