When the next Congress convenes in January 2019, there won't be a single Republican member who voted against the Iraq war, thanks to Rep. John "Jimmy" Duncan (R-Tenn.) announcing that he will not seek re-election.

Duncan's retirement is sad news that hasn't gotten the attention it deserves. The reliably conservative Duncan has quietly pushed back against a bipartisan foreign-policy consensus that has kept America mired in apparently unwinnable wars for nearly 17 years.

Duncan isn't alone as an antiwar Republican voice in Congress. After a short-lived "freedom fries" crusade, Rep. Walter Jones (R-N.C.) became a passionate opponent of the Iraq war and similar interventions. Sen. Rand Paul (R-Ky.) and Rep. Justin Amash (R-Mich.), meanwhile, are prominent libertarians who are as skeptical of war as they are of welfare.

But Duncan was one of just seven Republicans in either house of Congress who voted against the original authorization of the use of military force in Iraq, at a time when half the Democrats in the Senate (including Chuck Schumer, Hillary Clinton, and Joe Biden) were voting for war.

Four of those Republicans — Sen. Lincoln Chafee of Rhode Island, Rep. Jim Leach of Iowa, Rep. Connie Morella of Maryland, and Rep. Amo Houghton of New York — were among the most liberal remaining GOP lawmakers at the time of the vote in 2002. That left Duncan among three conservative Republicans, alongside Rep. Ron Paul of Texas and Rep. John Hostettler of Indiana, to vote against the war at a time when many argued that support for President George W. Bush's foreign policy was the very definition of conservatism.

The elder Paul later drew attention to an alternate libertarian-conservative take on foreign policy through his two Republican presidential bids in 2008 and 2012, spawning a small army of admirers and imitators who believe in constitutionally limited government and don't consider the Pentagon an honorary member of the private sector. But Duncan has largely remained an unsung hero.

Duncan is no pacifist. He followed most Republicans in voting for our first war in Iraq, Operation Desert Storm. And like every other Republican, he voted to retaliate against those who aided and harbored the murderers who attacked America on 9/11, though he hasn't been on board with the bipartisan commitment to remain in Afghanistan indefinitely.

So why did he vote against the Iraq war in 2002?

"I supported the first Gulf War because I went to all those briefings and heard Colin Powell and all of them say that Saddam Hussein was a threat to the entire Middle East," he told The American Conservative in 2005. "I saw his troops surrendering to CNN camera crews and I became convinced that the threat had been greatly exaggerated."

As George W. Bush famously said: "Fool me once, shame on ... shame on you. Fool me — you can't get fooled again."

Duncan wasn't fooled again. The second time Saddam Hussein was presented as an international menace who could only be dealt with through immediate military action, this time without committing an act of aggression first and with regime change as the explicit goal, he voted no.

Since then, Duncan has also opposed President Obama's "kinetic military action" in Libya, which like the Iraq war toppled a dictator but led to chaos afterward and ended up leaving Islamic radicals who threaten America and its allies with more power, not less. He has voted to withdraw from Afghanistan.

"There's nothing fiscally conservative about this war, and I think conservatives should be the people most horrified by this war," he said at the time. "We turned the Department of Defense into the department of foreign aid."

Duncan's views recently seemed to be ascendant in the Republican Party. In last year's primaries, voters rejected hawkish candidates like Jeb Bush, Marco Rubio, and Lindsey Graham in favor of Donald Trump, a man who criticized the Iraq war — in conservative, military-heavy South Carolina — in terms that nearly got Ron Paul tossed off the debate stage less than a decade before.

Trump has reiterated some of those criticisms as president, saying that the United States would be better off if Bush and Obama had gone to the beach during the time period when they were engaged in nation-building in the Middle East.

Yet there is a yawning gap between Trump's rhetoric and the reality of his administration. For Republican hawks, his presidency seems to be a "heads I win, tails you lose" proposition. We remain at war in Afghanistan. We are still intervening, without much fanfare, in Yemen. We have bombed Syria. We might shoot first and ask questions later in North Korea.

Trump's more hawkish advisers seem to have the upper hand inside the White House. And if Trump goes down, neoconservatives are well positioned to reclaim their lost influence, having warned the GOP against the president's flaws early and often via the "Never Trump" movement.

"I'm pro-military," Duncan once told The American Conservative, "but you can't give any department or agency in the federal government a blank check."

That seems like a good philosophy for our times. So why does Jimmy Duncan look like a member of a dying breed?