Rules of Engagement? Sending Troops to the Border is a Muddy Excercise


“They want to throw rocks at our military, our military fights back. I told them to consider it a rifle. When they throw rocks like what they did to the Mexican military and police I say consider it a rifle.” President Donald Trump, Nov 1, 2018

Sending troops to the border is a muddy exercise.

There are a broad amount of issues to deal with, both with US law, and international law. There’s the entire issue of The Posse Comitatus Act. Should US troops be able to fire upon people in Mexico? Should US troops be able to fire upon people in the US? Are US troops acting in a military operation perspective? Are they acting in a law enforcement one?

There are clear delineations between law enforcement and military operations. During a military operation, troops act using “Rules of Engagement,” (ROE). ROEs are developed at an international level, though there are exceptions. The Sanremo Handbook on Rules of Engagement is the main source, but it only serves to provide a framework. Each and every combat conflict has ROEs that are specific to it, yet don’t violate the overall spirit of the Sanremo Handbook.

During a domestic issue, when say the National Guard gets brought in because of a hurricane disaster, then it falls to the “Rules for the Use of Force,” (RUF). RUFs more closely follow the local laws of police actions. RUFs can vary based off of which law agency is running lead.

RUF can also be utilized when a host country has US (or other foreign entity) military personnel stationed there, like Japan, Germany, or South Korea. Between the host country and the US, there exists a “Status of Forces Agreement,” or (SOFA). Under SOFA, troops would look to RUF, as there wouldn’t be your typical armed combatant like in war. When it comes to the US/Mexico border, then there would be no SOFA, as US troops are not stationed inside of Mexico.

Since the troops stationed at the border are not dealing with US citizens, or are being hosted inside of Mexico, RUF would not be the defacto method of operation. ROE would be in play, as it’s the US border, looking into a foreign country. Those coming to the US border, however, are not armed combatants, but people looking to get political asylum or earn refugee status.

There is also the issue of the President’s word choices. Trump has said that we need to defend the border and that the caravan is an invasion.

As a military issue, and not a domestic law enforcement one, rules of engagement would have to be created and utilized. But that would only be the case while the people are on the Mexican side of the border. Once they’re housed within the US, as is often the case for those seeking asylum, there would be no rules of engagement, since US troops cannot operate inside the US border. It would switch to RUFs.

Even as the Commander in Chief of the Military, the president doesn’t have absolute authority as to what troops can and cannot do. By saying that rock throwers are the same as those with rifles wouldn’t exonerate any troop who shoots at a person on the Mexican side of the border. There are a lot of circumstances that would need to be dealt with, and too many “what if…” possibilities.

To keep it simple, for the most part, US military can shoot at armed combatants in foreign lands. Anything else is grey.

There hasn’t been a lot of info coming out of the Department of Defense on this. On October 26, they did release this two-paragraph statement on the roles of military personnel at the border. It seems that it is mostly logistical and rear echelon support, i.e. transport, equipment supply, medical triage. None of the tasks listed in the statement are those typical of an infantry unit, but could certainly be carried out by one, although not as efficiently as say the Army Corps of Engineers.

According to the statement, military personnel would not be serving in any type of leadership position, whether as law enforcement or border protection.

U.S. Northern Command, who oversees which units are deployed to the southern border, released a statement about the mission they’d be serving, and which units are actually going. Of the 38 units deployed, nearly all support. A few are military police, who will be used once the migrants are brought into the US, and put into temporary housing or camps.

In an email with NORTHCOM, spokesperson Lt Col Mary Ricks said the Custom and Border Patrol will still be lead agency at points of entry into the US, and that military police will serve solely in support of CBP agents.

But unless an individual military personnel is assigned to a civilian law enforcement agency, the agency is NOT in a military units chain of command. Meaning, no CBP agent has the authority to tell a soldier or Marine what to do. If a CBP agent were to direct the shooting of a person, and a soldier did, the shooting would be legal only if there was just cause, regardless of CBP instructions. Soldiers follow lawful orders from within their chain of command. That is it.

To drive this point home, even if an Air Force general were to tell an Army sergeant to fire his weapon, it wouldn’t be a legal order as the general is not in the sergeant’s chain of command, though both are in the military. It also doesn’t make the order automatically illegal, either. There could have been a clear and just cause to shoot.


Kurt Shrout is a former military police officer in the United States Marine Corps. He holds a BA in History and has traveled to over 70 countries, living in 3 of them. Follow him on Twitter.

This is an opinion piece. The views expressed in this article are those of just the author.

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