On Monday evening, an American Airlines flight from Miami, Florida to Barbados was boarded by a paramilitary police unit wielding assault rifles, who demanded that passengers put their hands on their heads as they were forced off the flight.

Large sectors of the airport were effectively placed under lockdown during the operation. The gates of terminal cafes and restaurants were closed, leaving patrons locked inside by iron bars as police SWAT teams decked out in body armor and toting assault rifles swept through the terminal.

Photos and videos posted to social media documented the egregious violation of passengers’ constitutional right to be free of unwarranted searches and seizures. “There were very large machine guns, body armor, all of that,” one passenger told a local CNN affiliate. “Very, very frightening.”

Some 70 flights were delayed and nine were diverted as a result of the lockdown, which shut down two concourses for almost three hours.

Officials claimed the cause of the lockdown was a breach in procedure by the Transportation Security Administration (TSA), which allowed a passenger who had been flagged as having a suspicious carry-on bag to board the plane. A TSA spokesman added that “in the process of transitioning other passengers to an adjacent screening lane, standard procedures were not adhered to and the passenger was allowed to depart the checkpoint and proceed into the terminal.”

The Federal Bureau of Investigation later admitted that the passenger was a dentist, and that the “suspicious” bag he had been carrying contained nothing more than fillings and other dental supplies.

TSA spokesman Mike England said that the lockdown was conducted “out of an abundance of caution” as federal officials “worked with airport operators to direct gate operations to cease while the passenger was located.”

He added that once the dentist was apprehended, “a manual inspection was conducted and law enforcement officers determined conclusively that neither the passenger nor his carry-on bag posed a threat.”

The incident took place amid the conspicuously growing incursion of militarized police, and even the military, into daily life in American cities. Even as the lockdown in Miami was occurring, flights at Los Angeles International Airport (LAX) were being diverted over populated sections of Los Angeles to accommodate secret military exercises taking place near the city.

Residents of the second-largest US city were startled Saturday to see a bright light in the sky over the Pacific Ocean, which military sources later said was a test of a Trident II intercontinental ballistic missile. Such missiles are used exclusively to deliver nuclear weapons; the Trident II deploys 14 separate warheads, each 30 times more powerful than the one that destroyed Hiroshima, although officials said the missile used in the test was unarmed.

In June, residents in Flint, Michigan were shocked to hear military helicopter landings, live-fire rounds and explosives being used in an office building in the city’s downtown, as military and police trained in the dead of night for snatch-and-grab and targeted assassination missions traditionally associated with paramilitary death squads. “We come in doing the hit, and extracting,” one military officer put it.

In December, 2,000 Marines staged urban warfare drills in Los Angeles, including the insertion of teams of heavily armed soldiers directly into the downtown area.

Such activities are accompanied by the increasing use of any pretense to impose paramilitary lockdowns on populated areas. Following the citywide lockdown after the Boston Marathon bombing in 2013, in which residents were told to “shelter in place” as armored vehicles patrolled the streets and police carried out house-to-house raids, any event, whether it be a prison escape, a minor security incident or even a weather event, has become a pretext to impose virtual martial law.

In June, at least 800 police and federal forces carried out a lockdown in upstate New York following the escape of two prisoners from Clinton Correctional Facility in the town of Dannemora in the Adirondacks. Militarized police wearing combat fatigues and body armor, and bearing assault rifles, forced businesses to close and prevented residents from traveling. After weeks of searching, officers shot and killed one of the escapees and wounded the other before taking a photo displaying the bleeding escapee as though he were a hunting trophy.

These events accompany the increasingly direct use of the military to crack down on popular opposition. Within the last 15 months, militarized police, accompanied by the National Guard, were repeatedly mobilized in the St. Louis and Baltimore areas to carry out mass arrests and shoot tear gas and rubber bullets at demonstrators against police violence.

While many of these incidents are presented by officials and the media as merely accidents or overreactions, they are in fact part of a systematic campaign to condition the US population to accept paramilitary tactics and violations of constitutional rights. Under conditions of growing poverty and social inequality, the ruling class can offer no response to opposition to its policies outside of turning to police-state methods traditionally associated with military dictatorships.