The year of the tactical vest

In late October, dozens of federal law enforcement officers flooded Canal street, a busy thoroughfare in Manhattan, arresting street vendors. Some officers donned full military uniforms; some wore plain clothes, baseball caps, and neck gaiters pulled over their faces. All were equipped with tactical vests of various styles and with a medley of identifying patches—“HSI,” “Customs and Border Patrol,” “Federal Agent,” or, simply, “Police.” They wore markers of power and authority, but...