A leaked internal FBI memo first reported by ABC News warns: “Armed protests are being planned at all 50 state capitols from 16 January through at least 20 January.”

Knowing what happened at the U.S. Capitol on Jan. 6, there have been calls to put state National Guard units on alert for possible support of law enforcement in responding to any such protests. This is a wise idea, but there are serious issues involving safety – including for the men and women of the Guard themselves.

Many of us watched on television when the D.C. National Guard was finally deployed to assist in securing the U.S. Capitol grounds. The Guard members I saw initially carried no weapons and wore soft caps. They were spread out behind a hastily erected chainlink fence, to serve as nothing more than a visual deterrent. The fence could have been easily scaled or knocked over, and the Guard personnel assaulted and bypassed. It may surprise people to know that the military is extremely reluctant to arm soldiers, other than specialized units, for protective domestic security missions and many overseas locations as well.

Visual deterrents work when people acknowledge the authority of the symbols and those who are empowered to use them. We know, for example, that we must stop when we see a school crossing guard or a school bus driver displaying their stop signs. Most of us do.

Unfortunately, use of unarmed National Guard members as visual deterrents may not work this time around, which brings into play the rules for use of force. National Guard units, since they belong to the states, are not given rules of engagement directives. Rules of engagement apply to active federal troops, usually in a combat zone. The two have much in common, but rules for use of force generally deal with domestic support to civil authority missions. Not enough police to deal with an armed mob of extremists? Call out the Guard.

However, the authorization for National Guard troops to apply force in support of law enforcement varies widely among the states. Some give them the full authority of police officers, such as Arkansas, while others, including Iowa, Nebraska and New York, allow them no more authority than private citizens. Maine statute authorizes our National Guard “to use all means necessary to protect its assets that are inherently dangerous or vital to national security.” Would this apply to protecting the State House, perhaps even the governor’s residence? What if rioters appear to be breaching the buildings, their intent unknown – should lethal force be used against them? Lawyers in Augusta are probably working on this issue now.

The U.S. Army Center for Law and Military Operations in Charlottesville, Virginia, recommends that states address the following key issues when issuing rules for use of force for National Guard forces: their right to carry and discharge firearms (especially in self-defense), their authority as peace officers and their authority for apprehension, search and seizure.

“We’re keeping a look across the entire country to make sure that we’re monitoring, and that our Guards in every state are in close coordination with their local law enforcement agencies to provide any support requested,” Gen. Daniel Hokanson, chief of the National Guard Bureau in Washington, told the Associated Press on Monday.

Expedient coordination and communication among the Maine State Police, the Capitol Police in Augusta, the Augusta Police, the Kennebec County Sheriff’s Office and the Maine National Guard are no doubt taking place as you read this. Hopefully nothing will come to pass regarding the FBI’s warning to our state. But hope is not a plan. Maine must stand ready to deal with the type of unprecedented, brazen violence that rocked our nation last week. The National Guard personnel who may be ordered to defend our state capitol against violent extremists must be properly equipped, and given the authority they will require.