1. The United States, financially teetering and unwilling to pay for the empire of bases that we have acquired since 1945, pulls up stakes and returns to the continental United States and what overseas possessions that are actually United States soil (say, Hawaii, Puerto Rico, the Marianas, and the rest of the Pacific Island possessions that we actually own outright).
2. The United States is economically still willing to pay roughly 2.0-2.5% of its GDP into defense; that number is currently between $276 billion and $335 billion in 2008 and would (hopefully) be closer to $400 billion in 2015. (Keep in mind, that the US defense budget has never been less than $317 billion in 2007 dollars since 1940). That number in terms of defense is slightly above average worldwide; the United Kingdom spends 2.4%, India spends 2.5%.
3. The United States is still a part of NATO, but has chosen to not forward deploy its forces in Europe. The same general treaty structure is in place in South Korea, Japan, the Phillipines, Taiwan, and Australia/New Zealand.
4. Oil prices have stabilized at the USD $200 level/barrel. With the rise of China, India, and continued tension between the remaining players in the Middle East, I would consider a return to sub-$100/barrel prices unlikely although welcome.
So, how would you do it? Every projected technology that we have is still on the table; you're going to have a fair pile of money to spend as is, and the mission is now on the strategic defensive for the first time since before there was a country. I personally would do some of the following:
1. Reconfigure the fleet by removing the Gator Navy and building up the SSN fleet. Remember, we're not kicking in any doors anymore. SSNs can deny the sea to any Great Power enemy that would look to attack any of our still active allies.
2. Reduce the size of the active-duty Army. What land-based security threats do we have worth an army of 500,000 regulars?
3. Retire the B-52 fleet if we can modify the B-1 and B-2 fleet to carry the same munitions. Their main job would be to act as a survivable heavy anti-shipping platform, as well as their role in the nuclear triad. Does the current B-1 and B-2 fleet have Harpoon capability? The B-52H fleet still does as of 1998.
4. Continue the buys of the F-22 and F-35 aircraft. This will continue the American advantage in aerial combat; the existing F-15C fleet is old and wearing out and the F-16 fleet cannot itself last forever.
I'm sure that there are many other things to be done to shift the American military from the offensive to the defensive, but I'd like to hear your ideas.
