Squads of heavily armed men, often in uniforms without identifying insignia, attack suspected enemies of the state, throw them into unmarked cars, and carry them away. This is the scenario that has unfolded in Portland, Ore., over recent days. Although it is new in the United States, in other parts of our hemisphere it is a familiar tactic. I saw it many times during years of covering repressive regimes in Latin America.

In Argentina during the 1970s, secret police officers would arrive at the homes of dissidents, usually at night, and grab their victims without identifying themselves. For decades in Guatemala, men with no insignia regularly attacked protesters. In El Salvador during the 1980s, newspapers carried almost daily reports of kidnappings and killings carried out by what were chillingly described as “heavily armed men in civilian clothes.”

Police in every country have a duty to maintain order. Some do it more harshly than others. Yet in a state of law, police officers should be identifiable, either by name or badge number or through insignia that shows who they work for. The use of paramilitary squads, whose members apparently work for the government but are otherwise unidentified, is deeply anti-democratic.

This approach to repression was not born in Latin America. During World War II, Nazi administrators in occupied countries were instructed to deal with troublemakers through a policy called “night and fog.” Night is when victims were abducted, and fog was all that their loved ones encountered when they tried to find out what had happened.

Conditions in Portland are hardly that dire. Death squads, secret detention centers, and clandestine executions are not part of American life. The use of unidentified police, however, takes us across a scary line. It gives officers anonymity that shields them from accountability.

What makes the situation in Portland so extraordinary is that these enforcement squads have been deployed against the will of the mayor and the governor. The state’s two senators, decrying what they call “paramilitary occupations,” have introduced a bill they call the “Preventing Authoritarian Policing Tactics on America’s Streets Act.” One co-sponsor, Senator Chris Murphy of Connecticut, made the essential point: “Without identification there is no way to hold these officers accountable, and there is no way to know if they are really federal officers.”

By coincidence, protests erupted in Portland as anti-government demonstrations were also raging in Hong Kong. In both places, some protesters have been violent, breaking windows, setting fires, and in the case of Hong Kong even invading and occupying the airport. Yet American politicians who cheer the protests in Hong Kong denounce those in Portland. Senator Ted Cruz has called the Hong Kong protests “an existential battle for liberty,” but condemns the protesters in Portland as “violent criminals seeking to destroy America.” Senator Marco Rubio lamented that police in Hong Kong are “so brutal to the people of Hong Kong, young and old, who are protesting.” Yet he supports federal police actions in Portland because there, “extremists are taking advantage of demonstrations to instigate violence.”

Shedding crocodile tears for victims of police repression in other countries is an old habit in Washington. These days, much outrage is directed toward the government of Nicaragua, which over the last two years has used brutal tactics to crush a widely popular protest movement. That repression has been carried out by squads made up of police operatives and armed civilians, usually wearing ski masks or other face coverings. Earlier this year the US Treasury Department imposed sanctions on Nicaragua’s national police and three police commanders. Treasury Secretary Steven Mnuchin said he acted because Nicaraguan police were engaged in “a campaign of violent repression.” He said the United States rejects police operations that “seek to silence pro-democracy voices.”

When the coronavirus crisis exploded in the United States, President Trump insisted that responsibility for dealing with it lay not with him, but with governors. Yet his belief in states’ rights evidently does not extend to law enforcement. Oregon Governor Kate Brown begged the acting secretary of homeland security, Chad Wolf, who is overseeing the armed squads patrolling Portland, to remove them and leave the job of crowd control to local and state police. Wolf was unmoved. “I don’t need invitations by the state, state mayors or state governors to do our job,” he asserted. “We’re going to do that, whether they like us there or not.” Governor Brown concluded that “he is on a mission to provoke confrontation for political purposes.”

Whether protesters pose such a danger to public safety that they must be violently suppressed is a legitimate subject for debate. Yet in responding to protests, political leaders should respect two principles: The choice of tactics should be up to state and local authorities, and the officers sent to restore order should be identifiable. When we abandon those principles, we embrace the repressive practices that we so vigorously condemn in others.