Since the US has secured the unofficial position of world policeman, the number of wars across the planet have been steadily decreasing. Most developed first world countries have military treaties with the US, giving them an unparalleled level of security. With American protection, various first world nations have decided to focus more of their money into nonmilitary programs, greatly increasing their standard of living.
The world is a cruel place and although the United States itself is cruel, it ought to maintain the most heavily invested and most powerful military in the world for freedom and peace. If it is weak, dictators and terrorist will plunder on the poor and innocent people. Only the United is trusted to step in.
America will go to war with China within twenty years, alliances are already being made, battle lines are being drawn, bombs are being built, ships are being constructed, the cold war continues into the 21st century with a new face on the opposing side. We live in the year 1900, in the sense that the great war machines of the world are already in motion, and it is only a matter of years before they collide no matter the circumstances. The drums of the third world war beat distantly on the horizon we and they believe it is us and them and we will all be smited for our hate of each other.
The US should not have to police the world alone. Germany, Japan (which is recently amending its constitution so they can have a real military), South Korea, the Netherlands, Belgium, Sweden, Canada, France, ... Those countries should step up and help. We basically agree with them when it comes to politics and human rights so we can trust them. Our treaties with these nations should require that they invest more in their own militaries so they can lend a hand when there is an international crisis. Of course they will have their own judgments about when intervention is necessary and when it's not, but we should at least get them to prepare. There are so many atrocities such as in Rwanda and now in the DRC where intervention would've helped but the political will is lacking. If we can't get an international consensus many will oppose intervention either seeing it as imperialism or seeing it as "not our problem". If these other countries had stronger militaries it would've been easier to promote an international consensus and get involved.
We should make the case that we need a coalition of nations to go in against ISIS and to stop ISIS in Libya, stop terrorists in Yemen, and stop Boko Haram. And the United States should not be left shouldering the entire burden.
It will be difficult for the U.S. to maintain its military when the dollar collapses. The U.S. is going the way of Greece and has been living beyond its means for far too long. Furthermore, the U.S. spends more on the military than is required to feed, clothe and house the entire planet. It is going to be very difficult indeed to maintain the U.S. military and pay its personnel when there is no money in the coffers. Somehow I highly doubt the rich elites are going to rise to the occasion to keep the system going. I guess we will see whether the Buffet's in the world are patriots or traitors when the time comes.