Twenty-three years after President George W. Bush's campaign of "shock and awe," the U.S. military has completed its withdrawal from Iraq.

ELISSA NADWORNY, HOST:

The U.S. military withdrew from Iraq this week 23 years after its invasion toppled Saddam Hussein and led to a security vacuum, insurgency, civil war and the rise of ISIS that kept the U.S. there for two decades. NPR's Jane Arraf, who has reported from Iraq since the 1990s, joins us from Baghdad. Hi, Jane.

JANE ARRAF, BYLINE: Hi, Elissa.

NADWORNY: So the Iraqi government declared a national holiday and held celebrations. Tell us about the significance of U.S. forces withdrawing.

ARRAF: Well, there weren't a lot of troops left. You know, at the height of the U.S. military presence here, there were 170,000, and recently, that was down to about 1,500. And the U.S. military had left once before in 2011, when it was relatively stable here. Iraq wanted them to leave. But then they invited them back three years later to help fight the militant group ISIS. And that's what they've been doing here until this week.

NADWORNY: So Iran had demanded that U.S. forces withdraw from neighboring Iraq. It wasn't happy about having U.S. bases right on its doorstep.

What's been the reaction there?

ARRAF: Well, Iran has painted it as a victory, as have Iran-backed militias who have been attacking U.S. forces and diplomatic missions here in Iraq. So there are two big developments here. One is that departure of the U.S. military, and the other is the Iraqi prime minister's promise to President Trump that he'll disarm those militias. That deadline has moved into next year. It's a very tall order. But - and this is also really significant - the hardest line militias announced this week that they would halt attacks, apart from shooting at enemy aircraft. Disarming, though, is a step further.

NADWORNY: And what's been the reaction among Iraqis?

ARRAF: Well, they like the idea, certainly, of foreign troops out, for the most part. At the tourist site of Babylon yesterday, we spoke with an Iraqi schoolteacher, Eshwa Saoud (ph). She was there with her family.

ESHWA SAOUD: (Non-English language spoken).

ARRAF: She said, "we think it's better for Iraq. It's our country, after all."

NADWORNY: Are there any worries about the U.S. withdrawal and where that basically leaves Iraq's ability to even defend itself?

ARRAF: A lot of worries in the Kurdistan region, the semi-autonomous region of Iraq, which has been hit hard by Iranian attacks. They host opposition bases there, armed Iranian opposition bases. So there's a lot of uncertainty there and a feeling of betrayal. And we have to remember the U.S. still has a lot of power over Iraq - financially, politically, even down to determining who the prime minister is here. President Trump boasted about that. We spoke with former foreign minister and Deputy Prime Minister Ali Allawi. Among his books is one called "The Occupation Of Iraq: Winning The War, Losing The Peace." Here's his take on the United States.

ALI ALLAWI: I mean, I accuse it of being indifferent and incompetent - indifferent to the outcome, incompetent in managing it. I mean, don't go around invading a country and send your troops, you know, thousands of miles and then wash your hands of the whole affair like punch a spider (ph).

ARRAF: So the U.S. toppling of Saddam Hussein dismantled the Iraqi military and then opened the door for Iran, destroying government institutions here, encouraging staggering levels of corruption. Allawi says that we'll need a generational shift to address that.

NADWORNY: A generational shift - that was NPR's Jane Arraf, who joined us from Baghdad. Thank you.

ARRAF: Thank you.