Already a leading GOP voice on international affairs, veteran Sen. John McCain of Arizona may further cement that role by joining the Senate Foreign Relations Committee next year.

McCain is currently the ranking Republican on the Armed Services Committee, but he is stepping down from that post at the end of the year because of party-imposed term limits and mulling adding Foreign Relations to his committee roster, he confirmed Friday. His membership on the Foreign Relations panel would instantly raise the profile of a committee that has become something of a backwater for Republicans in recent years and would add a mercurial new variable to the committee’s policymaking and interpersonal dynamics.

“I was thinking about it, yeah, I was thinking about it. It would be fun,” McCain said Friday when asked whether he is considering joining the panel.

“There’s some good people on there,” he continued, noting that he and Sen. Bob Corker, R-Tenn., the favorite to take over the ranking Republican slot from retiring Sen. Richard G. Lugar, R-Ind., “have a real good relationship.” Committee Chairman John Kerry, D-Mass., “and I have a very good relationship” as well, he added.

Indeed, McCain has been an important booster for Corker’s bid to become the ranking member of the committee, offering some cover from conservative criticism that the Tennessee lawmaker has been too willing to work across the aisle.

And McCain has a long-standing relationship with Kerry, with whom he has worked on foreign affairs and national security issues since both joined the chamber in the mid-1980s.

But the senior senator from Arizona and 2008 Republican presidential nominee also espouses a very different ideology on foreign policy from either Kerry or Corker. And by dint of his prominence in the party and in the media, he would come to the committee with his own platform and power base, creating a third locus of influence that would be separate from, though sometimes aligned with, the panel’s two leaders.

McCain’s activist agenda would align him more with Kerry on issues like intervening in Arab Spring-related conflicts, although McCain has gone much further than Kerry in calling for airstrikes in Syria, for example. Corker is far more skeptical of international intervention.

On the flip side, McCain has miffed Democrats with his strident critique of the Obama administration’s response to the terrorist attack on the U.S. consulate in Benghazi, Libya, and particularly of the role of Susan E. Rice, the U.S. ambassador to the United Nations and possible secretary of State nominee. He and Corker could team up to block Obama administration priorities or pressure Kerry to take committee action at odds with the White House — on Iran sanctions, for example, or confrontation with Russia.

All three men back active international engagement and foreign aid spending and have teamed up to oppose draconian cuts proposed by some conservatives.

But McCain breaks with both Kerry and Corker, and much of the rest of Congress, in his calls to slow the withdrawal of troops from Afghanistan and in the sort of troop presence he would like to see there after 2014.

Of course, the overall dynamic could shift further if Kerry leaves the Senate to join President Barack Obama’s cabinet.

McCain said Friday that he does not expect to make his decision “for the next few weeks,” and much will depend on how the committee lineup shakes out on Foreign Relations and other Senate committees. “It would be like my third or fourth committee,” he noted, which would require a waiver from Republican leadership, though that’s something he thinks he could get. McCain currently serves on Armed Services; Health, Education, Labor and Pensions; Homeland Security and Governmental Affairs; and Indian Affairs.

The Foreign Relations slot should be there if he wants it — and if the leadership acquiesces. Of the nine Republicans currently on the panel, the only two who are highly likely to return next year are Corker and Sen. Marco Rubio, R-Fla.