WASHINGTON (AP) — Two years ago, Sen. Bob Corker wondered aloud whether the standstill Senate was worth a grown man's time.

Now the combination of Republicans' political fortunes in last November's elections and brutal terrorism overseas has put the two-term Tennessee lawmaker in the limelight. He heads the Foreign Relations Committee and is in charge of the weightiest question to face members of Congress: whether to authorize war.

"I think all of us want to be productive in life. It was like watching paint dry," Corker, 62, said of his first eight years in the polarized Senate. "Yes, I do find myself in this second term in a very different place. I'm very glad I ran for re-election."

Less than two months into the Republican-led Congress, Corker is shouldering closely-watched global and political challenges. He is the face of the Senate's response to President Barack Obama's formal request to Congress for a new authorization for the use of force against Islamic State militants. And he is certain to play an outsized role in the congressional response to negotiations involving the U.S., other Western powers and Iran over its nuclear program.

As early as next week, Corker will gavel open Senate hearings on U.S. military intervention — a proxy, in some ways, for the broader debate over the nation's role in overseas conflicts in the post-Sept. 11 age of terrorism.

The affable shopping center builder and former mayor of Chattanooga also carries a hefty share of his party's drive to show the nation and the world that the new GOP majority can govern.

There's no tougher or more visible test of the party's lawmaking acumen than Obama's draft war powers request, which landed on Capitol Hill with a thud.

The U.S. military has waged an extensive campaign against the extremists for months, deploying more than 2,700 troops to train and assist Iraqi security forces and conducting airstrikes against targets in Iraq and Syria. Obama wants new authority to use against the Islamic State group, which has sparked international outrage with videos of their beheadings of hostages and burning of a Jordanian pilot.

Saying he was determined to avoid another long ground war in the Middle East, Obama submitted a use-of-force proposal last week that would expire after three years and bar the sustained commitment of American ground forces. The fight would be unbounded by national borders.

Obama's request is a starting point for the war debate. Corker will steer hearings on the parameters of any military action, from limits on time to its geography, and try to produce legislation that gives Obama the authorization.

Conservatives generally want broad authorities for the president, with no limits on troops. Other lawmakers want the new war powers narrowly defined to allow the president to train and equip local forces and conduct airstrikes, but not launch a ground combat mission.

Corker's Democratic predecessor as Foreign Relations Committee chairman, Bob Menendez of New Jersey, said Corker's challenge is "finding the balance of getting (Republicans) to move from the perspective of no limitations to some reasonable limitations and from Democrats who want to see very significant limitations to more reasonable limitations."

The gravity of the issue, and his outsized role, isn't lost on Corker. He says he'll conduct three or four weeks of hearings in hopes of finding any common ground between Obama's request and the array of variations sought by Corker's colleagues.

"Bob starts with a prejudice for consensus," said Sen. Chris Murphy, D-Conn., a member of the Foreign Relations panel. "Bob's not going to hesitate to stand up for his values or ultimately do something only with members of his party, but he starts with the supposition that it's better to do something in a bipartisan way."

Republican Sen. Jeff Flake of Arizona said Corker, who spent the congressional recess traveling in the Middle East, "doesn't come in with any preconceived notions or try to take partisan advantage of this. This is foreign policy. It's typically done across the aisle."

In recent years, the administration has often had more success in making its case with Corker than with Menendez, now the ranking Democrat on Foreign Relations. Menendez has been highly critical of Obama's efforts to normalize relations with Cuba after a half-century standoff, and of negotiations with other Western powers and Iran on its nuclear program.

Menendez last month blasted the administration, saying "the more I hear from the administration and its quotes, the more it sounds like talking points that come straight out of Tehran."

Corker has been more cautious in his public comments, and administration officials say privately that he is a man they feel they can do business with.

"He's more focused on getting things done than he is on endless ideological fights to score points," said Sen. Chris Coons, D-Del. "And in the environment of the current Senate that is a rare and important skill set or orientation."