Marines are headed to Los Angeles as the Trump administration ratchets up tensions that threaten to turn largely peaceful protests there into a full-blown crisis. It’s a rare and aggressive step to involve active-duty troops in civilian law enforcement activities.

A defense official, speaking on the condition of anonymity for fear of retribution, called the activation of the Marines a “provocation” designed to foster to a “manufactured crisis.”

Experts question the legality of the mobilization of the Marines.

On Saturday, President Donald Trump took the already extraordinary action of calling up more than 2,000 National Guard troops to tamp down demonstrations in California. In doing so, he exercised rarely used federal powers that bypassed Gov. Gavin Newsom’s authority.