Of course he had to resign.

To his credit, even though he was at the center of a burgeoning scandal, former CIA Director David Petraeus had sense enough to see that the leader of the nation’s principal intelligence agency could not deal with both a personal scandal and, simultaneously, answer tough questions about his agency’s role in the Benghazi attack that claimed four American lives.

Members of Congress insist on getting to the bottom of what happened in the consulate attack in Libya, as well they should. They need to know what the CIA knew and when, whether it failed to provide timely intelligence to the White House and the rest of the government.

Above all, they need to investigate whether lives were lost due to intelligence failures by the CIA or any other U.S. agency.

Gen. Petraeus decided to deal with his twin headaches by getting ahead of the personal scandal and making the issue of his own leadership moot. He resigned before detractors demanded his scalp so that he could face the Benghazi controversy squarely, without having his continuing role as head of the CIA come under fire.

The 60-year-old general also realized that he had failed to live up to his own ethical standards (and how!) and took it upon himself to act accordingly. He made a big mistake and he took a big fall. He offered no excuses and he spared his agency from the fallout.

There are several lessons here for other public officials caught up in personal scandals, mostly about how to respond appropriately and what “accountability” means.

Now the scandal has spread to other players, including Gen. John R. Allen, the top U.S. commander in Afghanistan. As Congress and the public sift through the headlines to learn whether harm has been done to national security, it’s worth keeping everyone’s eyes on the ball:

• Don’t be distracted from the main agenda. President Obama and Congress must agree on a tax-and-spending deal before the end of year to avoid a series of unwise, across-the-board spending cuts and tax increases on most taxpayers that have been written into law. This directly affects the public purse strings and the family pocketbook. Investigate Benghazi and the sex scandal, but keep in mind that avoiding the “fiscal cliff” is Priority No. 1.

• No scapegoats. Republican Sens. John McCain of Arizona and Lindsey Graham of South Carolina are ready to pin the blame on U.N. Ambassador Susan Rice, who early on said publicly that what happened in Benghazi was a spontaneous mob attack, not a planned terrorist action. If she was only reflecting the best intelligence available to the administration at that moment, she must not become a scapegoat. Get to the bottom of the Benghazi attack, but don’t turn what should be a serious investigation into another political circus.

• Don’t make this a partisan issue. It isn’t one — so far. The chair of the Senate intelligence committee calling for an investigation is a Democrat, Dianne Feinstein. But demands by Sen. McCain and others for “Watergate-style” hearings are overblown.

There are legitimate questions about Benghazi, but comparing a security lapse at a consulate with a historic event that produced Washington’s biggest White House scandal during the Nixon administration suggests that heated rhetoric is already drowning out reasonable judgment.

Gen. Petraeus, now out of government, has volunteered to testify at the hearings. Let’s hear what he has to say before jumping to unwarranted conclusions.