In his confirmation hearing to be secretary of the perennially troubled Department of Homeland Security, Jeh Johnson emphasized that his priorities would be to fill senior DHS vacancies, improve its management and raise its morale.

But now that he's on the job, Mr. Johnson is responsible for more than just the DHS. He also helps lead the National Central Bureau, through which the U.S. works with Interpol. The bureau's budget is only about $30 million, but that is no measure of the troubles it can cause.

To be fair, today's problems at the NCB are not internally generated. That was not always the case. In 2009, an audit revealed that the bureau was failing to cooperate effectively with the FBI and thereby "increased the potential that high-risk, violent criminals can enter [the U.S.] undetected."

Since then, the NCB has responsibly improved interagency cooperation. Today, it has personnel detailed from 29 federal and local agencies helping coordinate efforts. The problems at the NCB today center on Interpol itself.

Make no mistake: There is a real need for an organization that helps law enforcement agencies around the world work together to arrest and extradite criminals. If Interpol did not exist, we would have to invent it.

Nor should anyone be distracted by the Hollywood version of Interpol, which invariably features gun-toting agents working alongside the FBI. The reality is that Interpol is more like a bulletin board where the world's nations post their wanted notices. It's still national police that do the arresting.

In theory, Interpol's constitution prevents it from becoming involved in political, religious, racial or military matters. It's supposed to help its members pursue only genuine criminals.

But in practice, too many of Interpol's member nations don't respect this prohibition. They increasingly seek to use Interpol to harass unlucky business executives, dissidents and political opponents.

On occasion, Interpol rejects these efforts, as it did with Russia's effort to persecute William Browder. Mr. Browder is the London investor who leads the campaign for justice for his attorney, Sergei Magnitsky, who was killed after he uncovered a massive Russian tax fraud.

Too frequently, however, Interpol goes along with the autocrats. It did just that in the case of Ilya Katsnelson, an American businessman held in a German maximum-security prison for two months in 2008 on the strength of a ridiculous Russian wanted notice endorsed by Interpol.

More recently, Interpol targeted Estonian politician and American ally Eerik-Niiles Kross, again at Russia's behest. Interpol is discrediting its own valuable work. And it is ruining lives — attracting Interpol's attention can close your bank account and make travel impossible.

As the new head of DHS, Mr. Johnson can take three steps to help return Interpol to its proper role. First, he can establish a clear internal process for assessing whether a particular Interpol case is political, and an equally clear process for ensuring that DHS and other departments protect the rights of individuals wrongfully targeted by Interpol.

Second, he can help open Interpol to the disinfecting power of sunlight. By publishing a redacted report on the NCB's work with Interpol, and by urging Interpol to release similar information about the process by which it assesses cases, he can promote a more open culture that would expose abuse of Interpol by certain member nations.

Third, he can exercise the U.S. right to oppose unjust Interpol actions. Shockingly, the U.S., like other democracies, rarely challenges the politicized use of Interpol's channels. In answer to a question from Sen. Benjamin L. Cardin, Maryland Democrat, Mr. Johnson described the U.S. bureaucracy in such cases as "impenetrable and uninterested." That complacency should end.

As a distinguished lawyer and the Pentagon's top attorney in President Obama's first term, Mr. Johnson knows that law enforcement agencies do not exist merely to catch criminals. They also must protect the rights of the accused. If the new secretary can use his co-leadership of the NCB to remind Interpol of that fundamental fact, he will have met another great management challenge.

 - Ted R. Bromund is a senior research fellow at the Heritage Foundation.