The state of Minnesota’s “urban warfare” rhetoric is the inevitable consequence of this decades-long militarization of American police departments, Arthur Rizer, a policing expert at the center-right R Street Institute, told me late Saturday.

“You create this world where you’re not just militarizing the police—you equip the police like soldiers, you train the police like soldiers. Why are you surprised when they act like soldiers?” Rizer, a former police officer and soldier, said. “The mission of the police is to protect and serve. But the premise of the soldier is to engage the enemy in close combat and destroy them. When you blur those lines together with statements like that … It’s an absolute breakdown of civil society.”

American police officers generally believe that carrying military equipment and wearing military gear makes them feel like they can do more, and that it makes them scarier, Rizer’s research has found. Officers even acknowledge that acting and dressing like soldiers could change how the public feels about them. But “they don’t care,” he said. Most of the time, heavily armed police units such as SWAT teams are used not for the hostage and active-shooter scenarios for which they are ostensibly designed, but instead for work like executing search warrants, a 2014 study found. And agencies that use military equipment kill civilians at much higher rates than agencies that don’t, according to a 2017 study.