James B. Comey is a former director of the FBI and former deputy attorney general.

Each day brings more images of dark-green-clad, helmeted figures striking and spraying unarmed protesters on the streets of Portland, Ore. The figures are federal officers, rejected by local leaders and embraced by President Trump, who speaks of spreading that federal presence to other troubled cities.

The idea of a shadowy, uninvited federal force is troubling, but it is not clear that federal officers in Portland are acting unlawfully. Federal and Oregon laws appear to offer wide latitude to make arrests and forgo identifying insignia in service of their mission to protect federal property, including courthouses. Maybe that should change, but current law appears to give them a lot of room.

What is clear is that they are acting stupidly, a mistake they may be about to repeat in other places, with lasting consequences for federal law enforcement.

With some protesters itching for street confrontations with officers in full tactical gear, federal officials are giving a small group of violent people what they want. And they are giving the citizens of Portland — and the rest of us, no matter our politics — what we don’t want: the specter of unconstrained and anonymous force from a central government authority. It has been the stuff of American nightmares since 1776.

Fairly or unfairly, visions of Department of Homeland Security officers in camo without apparent identifying insignia dragging people into unmarked vans are now seared into the collective memory. Federal law enforcement, like all parts of the justice system, depends upon the faith and confidence of the American people, a credibility now being spent, recklessly, by the Trump administration. And the Department of Homeland Security, a key element of this administration’s chaotic and often immoral immigration enforcement, had precious little credibility left to spend in the first place. Thanks to Portland, its cupboard is now empty.

And even if it weren’t behavior inconsistent with American values and self-defeating for the agencies involved, it is also just plain dumb to give protesters another sinister embodiment of the feds to rail against.

The costs to federal law enforcement will be enormous, and in some ways that will be hard to see. As with all federal law enforcement agencies, the components of the Department of Homeland Security that are now prominent in Portland depend upon relationships with local law enforcement. That has long been true for the Federal Bureau of Investigation and the Drug Enforcement Administration, two Justice Department elements that have not been evident in Portland. “The FBI does nothing alone” is how I often explained our dependence upon partnerships with local and state law enforcement. The willingness of cities, counties and states to contribute their resources — most importantly, their people — to our task forces was at the heart of the FBI’s and DEA’s success. Town councils and mayors around the country supported those relationships because they trusted us.

For Homeland Security, it will now be a long road back to trust and partnerships.

So it’s dumb and self-defeating on many levels for the feds to engage the way they have in Portland. No sensible law enforcement leader would approach it this way. Which begs a question: Is televised conflict the goal?

What better way for Trump to demonstrate to his followers that he is “your president of law and order” than to deploy highly visible federal officers, and in a way that is sure to invite violent conflict, which, of course, demonstrates the need for a law-and-order president?

And on it goes. The only thing damaged in the process will be the United States and the federal law enforcement agencies our country needs. Yet again, the craving of our president for reelection seems to override everything.

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