For a good part of my adult life I have studied civil-military relations. I have studied authoritarian and democratic variants, and I have studied them across countries and regions. I have also worked in and with several US security agencies and have lectured on the theme at a number of military institutions in the US and abroad. It is with that background that I say this:

Trump’s deputising of the military for domestic law enforcement is a slippery slope in US civil-military relations. It is partisan manipulation that risks creating serious institutional rifts within the armed forces as well as between the military and society. The president certainly has the legal authority to do so but he also has the constitutional obligation to do so only as a last recourse when the country is under existential threat. Previous instances of deploying the US military in domestic law enforcement roles may or may not have been in the spirit of the constitution, and the precedent is mixed. Sending the national guard to defend civil rights in the face of state opposition is one thing; sending in them to stop looting and rioting is another. What is happening today is similar but different, and worse.

Using federal troops to disrupt peaceful demonstrations is a violation of the constitutional spirit. Using federal troops employing tear gas, flash-bang grenades and rubber bullets to do so is an abuse of authority. Doing all of that in order to stage a presidential photo opportunity featuring Him flashing a bible outside a damaged church–as the head of what is supposed to be secular democracy–is beyond the constitutional pale.

That is the terrain of personalist, party and bureaucratic authoritarians that use the military as a praetorian guard. In the US the military swears an oath to the constitution, not the president, even if he is the nominal commander-in-chief. It swears to defend the US nation against all enemies “foreign and domestic,’ but not in a selective or partisan way. The military is subordinate to civilian political control but in exchange receives considerable institutional autonomy with regard to operational decision-making. It therefore could and should refuse to deploy force as part of a clearly unnecessary politically charged event and in pursuit of ends that are not commonweal in orientation. 

States can already call up their respective National Guards. As a federal district, the District of Colombia covers patches of federal land interspersed with city and private property. Guardsman from DC can certainly be called up by the president for law enforcement duties. Trump has ordered the mobilisation of these troops but also active duty and ready reserve military police units outside of the DC National Guard. That includes combat units such as the 10th Mountain Division, 1st Infantry Division and the 82nd Airborne Division’s Immediate Response Force. From early in the fray, military intelligence has been providing counter-protest contingency planning information to at least seven National Guard units.

Note that my immediate concern is not about a descent into civil war or the military having to choose sides in such an event. That is something for another day. Here my focus is on the concept and practice of US civil-military relations as an institutional foundation of the nation. If left unchecked or encouraged, Trump’s actions will tear at the institutional and ideological fabric of the armed forces and thereby undermine the implicit contract that lies at the heart of civil-military relations in the US.

That Secretary Esper and JCS Chairman Milley participated in the photo op charade and a subsequent walk-around with the DC Guard, thereby symbolically legitimising its partisan use, demands that they step down. So too should the unit commanders who refused to question the orders coming out of the White House or chain of command, especially those authorising the use of helicopters as crowd control platforms and blunt force against unarmed civilians exercising their First Amendment right. It is one thing for political appointees in civilian departments to bow to the preferences of the president. It is quite another when top military officials do so.

That is why the military risks institutional fracture if it continues to obey Trump’s orders about its deployment in the current context. The rifts could be between “constitutionalists” and “pragmatists” or “partisans.” It could cleave across service branches and/or between officer and enlisted ranks (known as horizontal and vertical cleavages). Ideological cohesion and corporate autonomy could be lost. All of this because there remains a strong virtuous streak in the military that rejects its politicisation for domestic partisan purposes, and yet it coexists with a hyper-partisan leadership and pro-Trump sentiment in the ranks. The constitutionalists need to prevail in any inter-service dispute about their collective future.

To reinforce this message, the time has come for the armed forces command and Congress to prevent an expansion of the US military role in domestic crowd control roles. The institutional integrity at the core of democratic governance depends on it.