For much of the past year, whenever a major new indictment has come down in special counsel Robert Mueller’s investigation, we’ve been showing you a version of this chart.

As Mueller’s probe into Russian interference in the 2016 election and potential coordination with the Trump campaign moved forward, the indictments stacked up with impressive speed. So far, Mueller has charged 32 people in connection with the Russia investigation, far more than other major special-counsel investigations like Whitewater and Iran-Contra yielded. (Among the special investigations on our chart, only Watergate has more.)

There’s a problem, though, with simply comparing the number of indictments in different investigations. That approach assumes that all the indictments are in the same general category. For the Mueller investigation, they aren’t.

The vast majority of the people charged by Mueller live abroad — specifically, in Russia. This means that unless the 25 Russians individuals accused of crimes related to election interference travel abroad, are arrested and turned over to the U.S. or are extradited by Russia, Mueller can’t actually prosecute them. So far, attorneys for only one of the Russian organizations have appeared in a U.S. courtroom, in an apparent effort to force the Mueller team to hand over relevant evidence to the Russian firm.

It’s not surprising that a special counsel charged with investigating Russian interference in a U.S. election would have an international scope, but it does distinguish the Mueller investigation from similar probes going back to Watergate. It also places serious limits on Mueller’s ability to move beyond indictments to obtain guilty pleas and convictions. The indictments of the 25 Russians are symbolically important, but they almost certainly won’t result in a trial or any resulting legal accountability — like a fine or prison sentence — for the people charged.

In addition to the Mueller investigation, there have been 10 special counsel investigations since 1973 that resulted in charges. Of those 10, only two clearly involved the indictment of a person living outside the United States, according to my review of news and government reports. Neither resulted in further legal action — at least, related to that investigation.

One involved Robert Vesco, a financier who had fled the country to avoid charges that he had swindled mutual fund investors out of hundreds of millions of dollars. He was living in the Bahamas and Costa Rica when he was indicted in May 1973, accused of fraud and obstruction of justice related to a $200,000 contribution he had made to Richard Nixon’s 1972 re-election campaign in an apparent bid to resolve his legal problems. Although Vesco’s case was part of the broader Watergate investigation, he doesn’t appear in the chart above because the indictment against him was filed before a special prosecutor was appointed. Vesco remained a fugitive for years and never stood trial in the U.S.

The other included a Singaporean businessman, Abdul Rahman, who was indicted as part of a minor Clinton-era scandal involving Labor Secretary Alexis Herman, who had been accused of taking kickbacks for federal contracts and soliciting illegal campaign contributions on behalf of Democrats. (Herman was not charged in the investigation.) Rahman was accused of lying about the source of $200,000 in Democratic campaign contributions and improperly making campaign donations as a foreign national. He was the only person charged, and the case didn’t move forward because he lived outside the U.S.

To get a sense for why domestic indictments are generally more consequential than international ones, look no further than Paul Manafort, former chairman for Trump’s 2016 campaign. Manafort pleaded guilty to a reduced sentence last week in exchange for a promise to aid Mueller’s investigation. It was a coup for the special counsel: Mueller had been trying to secure Manafort’s cooperation for months, but even after Manafort was convicted of one set of charges, he seemed initially unwilling to provide Mueller with information.

Manafort is cooperating at a pivotal moment in the investigation. There’s reason to believe that more indictments of Americans may be coming, based on who has appeared as witnesses before Mueller’s grand jury in Washington. Manafort could help get those indictments over the finish line. Manafort is also likely to be asked questions that may be answerable by only a handful of people — like the details of the infamous Trump Tower meeting in June 2016, when Manafort, Jared Kushner and Donald Trump Jr. met with a Russian attorney to learn about “dirt” on Hillary Clinton. And he could provide damaging information about other people in Trump’s orbit and maybe even the president himself.

It’s hard to say exactly why Manafort chose to work with the special counsel. However, Mueller applied a great deal of legal pressure before Manafort agreed to cooperate, including sending him to jail for two months on witness-tampering charges before the beginning of his first trial (on tax and bank fraud charges). Manafort, who is 69, could have spent the rest of his life in prison if he had been convicted in the second trial, which had been scheduled to start in Washington in September. It’s not hard to imagine why he might have decided to cooperate under those circumstances. But Mueller has no such leverage over anyone who is outside the country and won’t be extradited. And that’s why at this point, the 25 indictments of individuals abroad — impressive as they were in both number and content — have less of an impact on the future of Mueller’s investigation (and its implications for the president) than a domestic indictment like Manafort’s, which has the force of the American legal system behind it.