If Clinton wins her parties nomination for president we will miss out on an important and overdue debate concerning the role of the U.S. military. This is because in a general election the debate between her and her Republican would probably center over how engaged to be in foreign conflicts, not over we whether we should engage at all. Senator Sanders would open the debate up far further, and U.S. citizens deserve that debate.
It has long been held that the U.S. needs to involve itself in conflicts to “protect its interests”, these might include the operations interests of multi national corporations, access to strategic or important natural resources, or groups of U.S. citizens. A large part of this has been relieved with the domestic oil and gas boom in the U.S. The network of multi national corporations has become so diffuse it is hard to see that they represent our interests at all. It may be that the U.S. may need to move to protect some of its citizens, but that has not come into play in our recent conflicts.
Another reason which was given for recent actions was the promotion of democracy. When we see how our recent actions have played out it is hard to justify the wars we have engaged as a tool for promoting democracy. A big reason for this is, as is pointed out by Francis Fukayama, it is extraordinarily hard to establish democracies in countries which have poor or no civil institutions. This is often the case when one replaces removes a regime from power.

Another argument in favor of military action is the removal of dangerous weapons, nuclear, biological, chemical weapons, from countries. Since the Iraq war however this is not an easy excuse to justify, given the misleading information which lead to that war. Or as would be the case in a country like Iran or North Korea the engagement would wind up requiring a commitment to war far beyond what we have seen in recent memory, due to complications of regional alliances, or the sheer military preparedness of the target country.

It may also be possible to make the case that the U.S. is forced into this role by the sheer size and advancement of its military, that no other country is as fit to take on the role of the protector of western civilization and the stability of the global economy. This is probably the most straightforward reason. In relation to it could be said that in payment for this service the U.S. reaps special benefits from the world, its preeminence permits it the to be the issuer of the global currency of choice, etc., and that to abandon this role threatens chaos to global systems in trade, finance, security, and what have you.

The problem with this line of logic is that what the U.S. receives in return is really of benefit to the global economy, less so to the people of the U.S.
It is also problematic in that our efforts and strategies have ultimately proved more and more destabilizing to the global community. Our invasion of Iraq, which lead to the disintegration of Syria, our efforts in Libya, even our invasion of Afghanistan which was so justified have served to create great swaths of misery and violence.

It is, of course, possible to say that the world would be reduced to chaos without the influence of the U.S. Or that more nefarious powers would move into a vacuum created by the absence of the U.S. and these two arguments are really tied together. China or Russia would ultimately have little interest in having a Talisman or Isis run country in their sphere of influence, for that matter neither would India. While allowing these powers to clean up the messes might create prolonged conflicts the opposite might be true. The U.S. is more strongly bound to rules of war due to the strength of public opinion, China and Russia would be freer to wage actual war on these parties. A brutal observation to be sure, but given the West’s difficulty in eradicating its enemies a possibly pertinent one. In any rate perhaps it is time to let them deal with these issues of hard to root out guerrilla combatants and religious fanatics. The lesson that these enemies drain more from a nation state than conquering the yields seems to be clear.

So the U.S. wages these wars, and in return receives very little. It seems clear with the infatuation young people have with candidate Sanders that they are ready for a Europeanized U.S. Yet the costs of this always comes into question. So to them it would appear that for the sake of foreign military actions that accomplish little and yield less they are denied things like universal health care, paid family leave, or free college tuition. If the country had something tangible to show for these actions it would be one thing, but it no longer does. Not to mention the moral problems associated with these actions.

If Clinton is the nominee these arguments will never get made, if Sanders is they will, and they have to be because the next generation will eventually demand that.