Iraq is back as a political issue. News of U.S. airstrikes against Sunni militants in Iraq is more than a military and foreign-policy story -- it's also one that that raises three important questions back on the home front.
How does a war-weary nation react?
After 13 years of war -- in Afghanistan and Iraq -- the United States is a country that has no appetite for more foreign intervention.
More than 70 percent of Americans say the Iraq war wasn't worth it, according to a June NBC News/Wall Street/Annenberg poll. The same survey found the public, by a 50 percent to 43 percent margin, believes that the U.S. does not have a responsibility to assist the Iraqi government against insurgent troops.
An earlier NBC/WSJ poll, from April. found that 47 percent of the country wants the United States to focus less on international affairs. Just 19 percent wanted to focus more.
So that's the domestic backdrop to President Barack Obama's authorization -- and subsequent action -- to strike ISIS militants in Iraq.
And it's why Obama stressed that the intervention would be limited.
"As Commander-in-Chief, I will not allow the United States to be dragged into fighting another war in Iraq," he said Thursday night. "And so even as we support Iraqis as they take the fight to these terrorists, American combat troops will not be returning to fight in Iraq, because there’s no American military solution to the larger crisis in Iraq."
Strikingly, Obama has largely been giving the country the foreign policy it desires -- no U.S. combat boots on the ground in Eastern Ukraine, in Syria, and Iraq (though the U.S. does have hundreds of military advisers there) -- but has received no credit for it.
Just 36 percent of Americans approve of Obama's handling of foreign policy, according to the latest NBC/Wall Street Journal poll.
What's Obama's Iraq legacy?
Obama has always counted America's withdrawal from Iraq as one of his proudest achievements as president.
"Four years ago, I promised to end the war in Iraq. We did," he during his speech at the 2012 Democratic convention.
But since then, ISIS has taken over key parts of the country, due in large part to the Iraqi government's military and political failings.
And the current second-guessing -- should the United States have acted earlier against ISIS or intervened in Syria (whose civil war helped spawn ISIS) -- raises the question if the United States' withdrawal allowed the militants to overrun the country?
Or was Iraq broken beyond repair -- even with unconditional U.S. military support -- after the 2003 war there? Or even before that with the Shiite-vs.-Sunni conflict there?
How do Republicans, especially the prospective 2016ers, react?
Sen. John McCain, R-Ariz., and Lindsey Graham, R-S.C., released a statement Thursday night calling for even more action in Iraq. “We need to get beyond a policy of half measures. The president needs to devise a comprehensive strategy to degrade ISIS. This should include the provision of military and other assistance to our Kurdish, Iraqi, and Syrian partners who are fighting ISIS. It should include U.S. air strikes against ISIS leaders, forces, and positions both in Iraq and Syria."
Sen. Marco Rubio, R-Fla., has largely echoed that call. “ISIS’s continued rise is not just a problem for Iraq or its neighbors. If we do not continue to take decisive action against ISIS now, it will be not just Iraqis or Syrians who continue to suffer, it will likely be Americans, as a result of a terrorist attack on the U.S. homeland or on our personnel overseas,” he said in a Time op-ed.
But that kind of hawkish desire for more intervention runs counter to the foreign-policy vision of possible presidential candidate Sen. Rand Paul, R-Ky., who usually calls for more restraint.
"America cannot shrink from its role in the world. We have been and should be a shining example of good, and at times, a superpower of last resort to maintain peace and prosperity," Paul said in a speech in Nov. 2003. "To be engaged, though, does not always mean to be engaged in war."
Come 2015, one of the big storylines will be this fight inside the Republican Party -- between the more dovish Pauls and more hawkish Republicans.
And the longer the Iraq story plays out, the more it will highlight that intraparty fight.