DEBBIE ELLIOTT, HOST:

A historic milestone in Iraq this week - U.S. forces are withdrawing after a two-decade-long military presence that began with the invasion of Iraq that toppled dictator Saddam Hussein in 2003. It's a very different Iraq than the country the U.S. entered and a different America. NPR's Jane Arraf has been reporting from Iraq since the 1990s and joins us from Amman. Hi, Jane. First, tell us what's happening this week.

JANE ARRAF, BYLINE: Well, by Wednesday, the U.S. will have pulled out all the forces that have been operating under the anti-ISIS coalition that had formed in 2014. That's when the militant group ISIS took over roughly a third of Iraqi territory, and it's also when Iraqi army divisions that were hollowed out by corruption and sectarianism just collapsed. So the U.S. had left in 2011. They thought they were done. They had a ceremony. They got on military planes. This time, as they're leaving, there will be no fanfare. Central Command says there's no ceremony that will be open to the press. It will be a quiet withdrawal.

There are only a few hundred of the roughly 2,500 troops that have been here this year left anyway. And we have to compare that to the height of the war when there were something like 170,000. So this is a turning point for Iraq. It's under pressure from Iran-backed political parties and militias who have demanded that the U.S. military leave. And President Trump has pledged no more what he calls endless wars, including the one in Iraq.

ELLIOTT: We know that Iraq relied a lot on the U.S. military, including air defenses that have intercepted what is believed to be hundreds of Iranian missiles since the start of the Iran war. Where does that leave Iraq?

ARRAF: Well, in many ways, there's a much stronger Iraqi military than there had been before, and that's thanks to 23 years of training by the U.S. and other countries. But there are some capabilities it doesn't have, like intelligence and surveillance, air support. Those are the kind of capabilities that helped defeat ISIS territorially in Iraq in 2017.

But we have to mention that the big worry here is from the Kurds. They are a main security partner of the U.S. And that region, the Kurdistan region of Iraq, is now a main target of Iran and Iran-backed militias. So Kurdish leaders say almost a thousand drones and missiles have hit the region, and they say they have no air defenses, so they're left feeling very vulnerable.

ELLIOTT: That's been one of the themes of the post-invasion Iraq - hasn't it? - the increasing Iranian influence over the country, including the Iran-backed militias that have attacked the U.S. embassy and other targets. What is happening on that front?

ARRAF: Well, September 30 was also to have been the deadline for Iraq's new prime minister to disarm those militias and bring all weapons under control of the state. So that's a really tall order. Other Iraqi leaders far more experienced than he is have tried before and failed. The prime minister, Ali al-Zaidi, is a political newcomer, a former businessman, but Trump really likes him, so that's hugely important. He promised Trump, in a visit to the White House in July, that he'd have the militias disarmed by September 30. He is now saying that he actually needs until mid-next year, but the U.S. seems to be going along with that. Here's Secretary of State Marco Rubio last week.

(SOUNDBITE OF ARCHIVED RECORDING)

MARCO RUBIO: I think he has the right intentions. I think he has the right motivations. He's very intelligent and a very willing partner in this regard. And we're going to do everything we can to help him achieve the results, and we know it will not be easy. We know it will be difficult.

ARRAF: So that's expected to diffuse threats from the U.S. of economic measures if Iraq doesn't, in fact, disarm those militias.

ELLIOTT: Jane, the U.S. has invested so much in Iraq, including the lives lost - more than 4,000 U.S. military personnel. Tell us more about why the military is withdrawing now.

ARRAF: Well, that Iranian influence has grown since the U.S. opened that door by toppling an Iraqi dictator who was an enemy of Iran. So really, it became untenable for U.S. forces to stay. But also, President Trump made clear from - beginning with his campaign pledges that he wanted to end these kind of wars. Now, of course, there's the war he has started with Israel in Iran, but he denies that one will be an endless war.

Iraq, by the way, is still part of that equation of the war in Iran. There have been, recently, attacks on Saudi oil facilities that Saudi says came from Iran-backed militias in Iraq, although Iraq denies that. But the U.S. says it's focusing now on economic ties, not so much military ones. So Iraq is a major oil producer and potentially a huge market. And so the U.S. is looking at what it can do for the United States, with zero appetite for the kind of nation-building that we saw after the invasion.

ELLIOTT: So if they haven't yet, what are the prospects that those militias will actually hand over their weapons?

ARRAF: Well, at least three of the hardest-line factions say they won't. We sat down with a spokesman for one of them recently, a group called Kata'ib Sayyid ul-Shuhada. And he explained that, while, yes, their demand had been that U.S. forces leave, he says, well, it's still an economic occupation. And by that, he means that U.S. controls Iraqi oil revenue because it goes through the central reserve bank in New York. So that's a lot of leverage on Iraq. Still, this is considered a victory by Iraq and many Iraqis. The Iraqi government is calling it the day of sovereignty, and they've declared it a holiday.

ELLIOTT: Jane, you've covered the U.S. invasion of Iraq and the many battles that followed, a lot of it embedded with U.S. forces. Can you talk to us a little bit about how Iraq has changed regarding the U.S. military presence over the years?

ARRAF: It's changed so much. I really feel like there are several different Iraqs. You know, the first was a country that was literally run by Americans who knew so little about it. And then the soldiers I first met were told it would take six weeks and they'd be home. And then there was a security vacuum, an insurgency, and it dragged on for years and led to a civil war in which a group called Iraq Body Count says at least 200,000 civilians were killed. And some of those were killed - a lot of them were killed by American soldiers because they got too close to a convoy, or they misunderstood hand signals. There were so many places in their own country Iraqis couldn't go.

But, you know, it's a very young population, and now we've reached the point where a lot of young people - almost all young people - have never seen a U.S. soldier. So there are a lot of challenges ahead for sure, but Iraq does seem to have reached a point where it's largely in control of its own destiny.

ELLIOTT: NPR's international correspondent Jane Arraf, thanks so much for your insight here.

ARRAF: Thank you.

(SOUNDBITE OF VULFMON AND JACOB JEFFRIES' "BLUE") Transcript provided by NPR, Copyright NPR.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.