John McLaughlin is the former deputy director of the CIA. He writes a regular column on OZY called “Global Eye: Foreign Affairs Through an Intelligence Lens,” and teaches at the Johns Hopkins University’s School of Advanced International Studies (SAIS).

OZY Senior Columnist John McLaughlin teaches at the Johns Hopkins School of Advanced International Studies and was deputy director and acting director of the CIA from 2000 to 2004. Follow him on Twitter: @jmclaughlinSAIS.

The last several weeks have seen some of the worst and best examples of how Congress oversees American intelligence. The worst came in the performance of the House intelligence committee chairman, Rep. Devin Nunes, as he drove a wedge between Republicans and Democrats on his committee. The best was seen in the public hearing the Senate intelligence committee held last week with intelligence agency heads on worldwide threats to U.S. interests.

In the early years after World War II, as American intelligence was getting organized, Congress had only minimal knowledge and impact on secret intelligence activities. Basically, the CIA director would show up on Capitol Hill once a year, make his budget request and have a quiet conversation with a few senior senators — some of whom professed not to want to know too much.

This is the first time I know of when one party on these committees has pushed out a controversial view without allowing simultaneous dissent from the other party.

But in the mid-1970s, in the aftermath of the Watergate scandal and separate controversies about the CIA and FBI, Congress decided it needed to pay more attention. So in 1976 and 1977, Congress created the two intelligence committees — one in the House and one in the Senate.

These committees were to be special in a number of ways. They were to be nonpartisan, and the Senate and House leaders were to choose members with that quality in mind. The original contract was that they would have access to all the intelligence community does in return for discretion and a bipartisan approach to overseeing intelligence activities. They were empowered to hold hearings, carry out investigations, authorize the intelligence budget and get briefings on sensitive activities, including covert action.

This all worked reasonably well in the 1970s and 1980s, when the committees’ members — among the most senior and respected figures of the period — worked their way through divisive controversies such as the Iran-Contra scandal. But as partisanship deepened between the parties, it infected these committees too, starting especially in the 1990s. Members discovered that being on these committees got them TV time; they began dividing up what until then had been a strictly professional staff between the majority and minority parties. Since then, the committees’ culture has depended mostly on the personalities of their majority and minority leaders and whether they set an example of bipartisan behavior and enforced it. In recent years, this has been the exception rather than the rule.

Today, on the House side, Nunes has upended the process several times. This occurred most recently on February 2, when he gained approval by his party’s committee majority to make public a memo in which he accuses the Justice Department and the FBI of improper conduct. He asserts that they deceived the federal judges who must rule on warrant requests when the FBI wants to monitor the subject of an investigation. This investigation sought to determine whether a Trump associate, Carter Page, had improper dealings with Russia as it sought to influence the 2016 presidential election.

So what’s wrong with Nunes’ approach? Well, the Democrat minority on the committee has a dissenting view, but Nunes’ majority and the White House have thrown down one obstacle after another to delay it or keep this opposing view from coming out. This is the first time I know of when one party on these committees has pushed out a controversial view without allowing simultaneous dissent from the other party. Even in other harsh controversies, both parties have had their say. In 2014, for example, the tables were turned when a democratic majority on the Senate committee issued a report sharply critical of CIA interrogation practices. When Republicans took strong exception, the Democrats allowed them and the CIA simultaneously to publish separate dissenting views.

The bottom line is that Nunes, to discredit the investigation of Russia’s activities, has taken partisanship to a new low in a committee that deals with some of the nation’s most sensitive foreign and domestic activities — exactly the reverse of what these committees were created to do. He has substantially damaged the committee’s credibility and its ability to do its job. Moreover, the indictments Special Counsel Robert Mueller issued on February 16 knock the props out from under Nunes’ basic argument, which is that the Russia investigation has no basis in established fact.

The Senate committee historically has also had its highs and lows. But last week was a high point under Republican Chairman Richard Burr and Democrat Vice Chairman Mark Warner, who appear to have established and enforced a bipartisan environment on their committee. They held a hearing with five of the nation’s intelligence chiefs and questioned them publicly on a range of national security issues, including Russian interference in our elections. For their part, the intelligence agency heads showed the American public what speaking “truth to power” means as they did not shrink from stating candid views often at odds with those of President Trump and other political figures in the administration — on issues ranging from Russia’s meddling to FBI investigations of White House personnel. No spin; just the facts.

Why does the quality of congressional oversight matter? Two words: public confidence. Intelligence agencies are granted substantial power in our open, free society and our public has to have confidence that its elected representatives are carefully and jointly overseeing this in line with relevant laws — not playing political games. And for their part, responsible intelligence agency leaders support this process, because they know they need not only public confidence but also congressional judgment and buy-in for their most sensitive activities.

Our intelligence agencies are asked to undertake some of the nation’s most difficult and risky work. When its legal overseers pay more attention to partisan political battles than their real jobs, intelligence officers are left with the two questions that in recent years have most frequently haunted them: Who really understands what we’re doing? Who really has my back?