My colleague Ben Friedman has previously blogged on the brigade-sized homeland defense element that the Army is putting on standby for domestic emergencies. Like Ben, I think that this sets a bad precedent for future domestic military deployments.

Plenty of civilian officials and military officers share this sentiment and don’t want to make homeland security a military proposition, like this Air Force JAG officer writing on the fictional military coup of 2012, and this Army JAG reservist discussing the pre-9/11 erosion of the Posse Commitatus Act. It is worth noting that the Department of Justice would be the prosecuting agency for Posse Commitatus violations, so you would need an ahistorical self-policing executive branch to provide real deterrence.

So color me a little bothered by a joint military police-highway patrol DUI checkpoint. While it is passed off as a “show of good relations between our two departments,” it is not a sight that the American public should get too accustomed to. Neither is a National Guard exercise using a local town for cordon and search training. As a unit representative explains, “[w]e will need to identify individuals that are willing to assist us in training by allowing us to search their homes and vehicles and to participate in role-playing.” Count me out. At least the guy acknowledges that “this operation could be pretty intrusive to the people of Arcadia.”

In many ways, the line between civilian and military spheres of government is the line of liberty. Separating our common defense from our domestic tranquility was the vision of the Founders, and we shouldn’t turn our back on it lightly.

UPDATE: Since I wrote this, the National Guard decided to scale back the exercise. So much for my career as a Third Amendment crusader.