Ever since terrorists attacked the U.S. consulate in Benghazi, Libya, on Sept. 11, 2012, killing Ambassador Christopher Stevens and three other Americans, the event slowly has morphed from a tragedy into a synonym for the U.S. government's political paralysis.

After the release of more than 25,000 documents and 13 public hearings, still more inquires and public hearings are planned.

So it is welcome indeed that U.S. commandos, working with the FBI, entered Libya Monday and captured Ahmed Abu Khattala, an alleged participant in and planner of the assault. A leader of the Ansar al-Shariah terrorist group, Mr. Abu Khattal is under arrest and will be tried in the United States.

The investigation and operation marked significant progress in bringing justice to those involved in the attack. But, apparently, it won't bring any domestic progress. Congressional critics quickly switched from complaining that no one had been arrested to condemning the administration for planning to try the suspect in a federal civilian court, even though he could face the death penalty if convicted. According to the New York University Center on Law and Security, at least 337 trials were conducted by federal civilian courts from 2001 through 2009.

More than 70 people were involved in the Benghazi attack. Ideally, this arrest will be a step in bringing all of them to justice. Even less certain is whether it will turn the attention of Congress to justice rather than political retribution.