WASHINGTON — It may be hard to believe now, but there was a time when Congress showed very little interest in Libya.

On Thursday, the House voted along party lines, 232-186, to convene a select committee to investigate the Sept. 11, 2012, attacks in Benghazi, Libya, that killed four Americans, including the U.S. ambassador, J. Christopher Stevens.

Republicans said panel was necessary for Congress to carry out its oversight role into how the attack happened and whether the Obama administration purposely obscured facts afterward.

But the new Benghazi probe is unlikely to tackle another topic some argue is just as critical to understanding what went wrong in Libya: Congress’ failure to call attention to the deteriorating security situation after the NATO-assisted toppling of Libya’s longtime leader, Moammar Gadhafi.

Even after Congress approved the U.S. military joining a NATO mission in May 2011 whose efforts contributed to Gadhafi’s fall and death, neither the House nor the Senate held a hearing about Libya and what the mission had left behind.

After four decades of living under Gadhafi, Libya struggled to maintain security, its economy failed to recover and the government in Tripoli was powerless to fend off extremists who took control of the country.

Sen. John McCain, of Arizona, the senior Republican on the Senate Armed Services Committee, met with Stevens during a July 2012 visit to Libya, two months before Stevens’ death.

Yet McCain made no mention publicly of the deteriorating security situation and, instead, issued a news release that effusively praised the progress Libya was making toward democracy.

Asked this week about his visit with Stevens, McCain said the ambassador had discussed the security situation with him. Pressed for details, McCain said he could not remember the specifics.

Asked whether he brought any security concerns to the attention of Congress or officials at the State Department when he returned from Libya, McCain said he could not recall.

A review of Senate records found nothing to indicate that he had.

McCain acknowledged he didn’t probe. “I didn’t ask him questions,” he said.

McCain is not alone. Before the Benghazi attack, Congress showed little interest in developments in Libya after the collapse of the Gadhafi government.

Russia, which had joined the United States in supporting a U.N. resolution authorizing the use of force, later accused the West of exceeding its authority.

The chairman of the new House select committee, Rep. Trey Gowdy, R-S.C., voted for the resolution that allowed for U.S. intervention in Libya. But he also supported a later one intended to prevent the United States from providing the kind of military presence that some argue was needed to prevent Libya’s decline.

That resolution read in part: “The president has failed to provide Congress with a compelling rationale based upon U.S. national security interests for current U.S. military activities regarding Libya.”