May 17 at 5:11 PM

On Tuesday afternoon, a brief but violent altercation erupted outside the home of the Turkish ambassador on Washington’s Embassy Row. At least nine people were injured in the fighting. Video taken at the scene would indicate that most of the injured were protesters standing across the street from the ambassador’s residence.

At least some of those involved in causing the injuries were guards for Turkish President Recep Tayyip Erdogan.

It’s worth noting that this is not the first time that Erdogan’s bodyguards have been implicated in harassing or assaulting people on American soil. When Erdogan visited Washington in March 2016, Turkish journalists charged his guards with verbally attacking them and, in at least one instance, kicking a journalist hard enough to make him bleed.

But the incident on Tuesday was of another scale entirely. In the video, a group of men, many in suits and wearing badges, charge into the group of demonstrators, who were protesting Erdogan’s policies in Turkey, Syria and Iraq, according to a Facebook video. Turkey’s state news agency said the security team sought to disperse the protest because D.C. “police did not heed to Turkish demands to intervene” — sensibly, since American police are expected to allow peaceful protests to continue. After the fighting begins, D.C. police are seen trying to break up the brawl but appear outnumbered.

At a news conference, D.C. Police Chief Peter Newsham said that several of the guards involved in the melee were armed, making intervention “dicey.” He also noted that applying legal remedies might be tricky because some of those involved might have diplomatic immunity.

This raises two questions. First, to what extent can the U.S. government punish any of Erdogan’s guards who may have assaulted protesters? Second, how can the government keep this from happening, should Erdogan visit the United States again?

To answer those questions, I spoke by phone with David Stewart, professor at Georgetown University Law School, and Ruth Wedgwood, professor of international law and diplomacy at Johns Hopkins University. Both made one point clear: Diplomatic immunity was not a license to assault people on American soil and get away with it.

“Immunity is, in fact, a pretty limited protection for very specific purposes of government business,” Stewart said. Those with diplomatic immunity are granted that protection by the government out of its self-interest: We want our diplomats protected from spurious legal charges while they’re overseas. But we expect that legitimate concerns about illegal behavior by our diplomats will result in ramifications, just as we can hold accountable those with diplomatic immunity who behave improperly in the United States.

How? Although prosecutors in Washington can’t arrest members of Erdogan’s security detail if they have certain types of immunity, those individuals can be charged with any crimes they have committed — meaning that if those people come back to the United States in any nonprotected capacity, they can be arrested at that point. We can also expel those guards from the country, something that President Barack Obama did in December to punish Russian agents involved in hacking. We can also prevent them from coming back in.

The type of immunity that the guards might hold isn’t clear. The ambassador has full immunity. If the guards involved in Tuesday’s fracas are attached to the embassy, they may have similarly robust immunity, including “personal inviolability” — meaning they cannot be arrested or otherwise detained. If they were traveling to the United States as part of the president’s entourage — and if our government recognized those guards as being here in that context — they are covered under a similar principle of immunity. (The terms (The terms of immunity are spelled out in the Vienna Convention of 1961.)

Wedgwood notes a possible caveat: If the guards weren’t acting in their official capacity, that might change the extent to which they’re protected under immunity rules. Unsurprisingly, she was also skeptical that fighting with protesters would be considered an official act.

Immunity covers specific activity at a specific time. Those injured in the brawl could sue the guards or the Erdogan government. If Turkey wanted to, it could prosecute the guards when they return home — immunity wouldn’t offer protection from that, although Erdogan probably would. The United States could also leverage its political power to demand that Turkey compensate those injured and provide assurances that similar incidents don’t happen again — as the United States has, at times, been forced to make up for bad behavior by our diplomats.

Which brings us to the other question: How can the United States prevent a third year of brawling Turkish guards?

“The host nation — which is a term of art,” meaning that it is a defined phrase in international diplomacy, “has a great deal of flexibility: how many to let in, who to let in,” Wedgwood said. Erdogan can’t simply say that he is bringing a set group of people who therefore get immunity. Although the embassy itself is inviolable (though not sovereign territory), getting to that embassy requires permission from the United States.

Ultimately, the repercussions of the brawl come down to the will of the government — that is to say, the Trump administration — to decide how to address the guards’ behavior. Whether to expel the bad actors is up to the administration, as is how to constrain Erdogan in the future. D.C. police can identify the culprits in the fight, and the city can charge them with crimes, but beyond that it’s up to the executive branch.

On Wednesday, the State Department released a statement “communicating concern to the Turkish government in the strongest possible terms.” During a brief discussion with the media, press secretary Sean Spicer was asked for the president’s view.