Washington superlawyer Joseph Califano once passed a message to a client being grilled by a congressional committee that read: “Keep cool in Kabul.” Califano simply wanted to calm the witness, slow the process a bit and get everyone to chill out.

The advice seems especially useful now that Washington’s latest set of scandals is entering the phase of congressional investigation, righteous political indignation and public penance. At times like this, people tend to repeat the old bromide, “sunlight is the best disinfectant.” But it can also be toxic in the wrong circumstances.

The various scandals entwined around leading national-security figures have a common feature: They were all driven to the surface by the fear of political exposure. It’s worth considering for a moment the way in which politics — and the rush to get out ahead of anticipated disclosure — has driven this process and made it more damaging than it needed to be.

This nexus was spotted by Jane Mayer of The New Yorker in a recent blog post. She noted that the dominoes began to fall when a self-appointed FBI whistleblower went to Republican members of Congress, first Dave Reichert of Washington and then Majority Leader Eric Cantor, to warn them of a possible cover-up of the Petraeus investigation. Cantor’s staff called the office of FBI Director Robert Mueller, and the fat was in the fire.

Knowing that the supersensitive investigation (which apparently was then winding down) had become a political football, Mueller’s deputy Sean Joyce called Director of National Intelligence James Clapper on Nov. 6. Clapper summoned CIA Director David Petraeus, counseled him to resign and informed the White House. Three days later, Petraeus was gone.

Fear of political blowback also triggered the revelation that Gen. John Allen, the U.S. commander in Kabul, had been exchanging possibly inappropriate emails with Jill Kelley, the Tampa socialite, military liaison and, judging from what we’ve read, all-around busybody. The FBI had already reviewed Allen’s emails as part of the Petraeus investigation, but last Sunday afternoon (Nov. 11), the FBI decided to inform the Pentagon and turn over 20,000 to 30,000 pages exchanged between Allen and Kelley. Last Monday, Defense Secretary Leon Panetta decided to go public, open a Pentagon investigation of Allen and suspend his confirmation as the next U.S. commander in Europe.

Why did the Pentagon suddenly drop Allen into limbo? We still don’t know what is in the emails, beyond some “sweetheart” language. But Panetta clearly was worried about political fallout. Allen was due to testify before Congress last Thursday and, as a senior Pentagon official explained: “If you don’t inform Congress of the FBI referral, that becomes a problem.”

In the wake of the McCarthy investigations in the 1950s, when Americans wondered how responsible officials could have allowed such a reckless “witch hunt” that ruined reputations on the flimsiest evidence, Arthur Miller wrote “The Crucible,” about the Salem witch trials of 1692. The play’s genius was that it explained how sensible early Americans could have been swept up in a process of public shaming and destruction of character.

Many members of Congress talk as if the real outrage here was that they weren’t informed earlier about the investigations of Petraeus and Allen. “We should have been told,” said Dianne Feinstein, Senate Intelligence Committee chairman, last Sunday. To which an observer might respond vernacularly: Give me a break.

The idea seems to have developed that the CIA and the military work co-equally for Congress and the executive branch. They don’t. They work for the president, who is commander in chief. Congress appropriates the money, and has a legitimate role in overseeing how it’s spent. But the idea that these scandals demonstrate the need for greater congressional involvement in sensitive investigations is preposterous.

The day Petraeus resigned, I received an email from an Arab intelligence contact who expressed what surely has been going through the minds of many people around the world. I will quote it precisely, punctuation and all: “He needs to resign cause he has an affair? What da hell??? He is brilliant!!!! Why like this????”

Petraeus is gone, but the hunt for miscreants is still gathering force. For a reminder of why it’s dangerous, take a look at “The Crucible” and the lessons of history.

David Ignatius writes about foreign affairs for The Washington Post. He can be contacted at:

davidignatius@washpost.com