A convoy of U.S. and Kurdish army troops patrol near the Syrian-Turkish border. (Youssef Rabie/EPA-EFE) (Youssef Rabie Youssef/EPA-EFE/REX/Shutterstock)

If you want a reminder of the whiplash that is U.S. Syria policy, consider this:

Last week, Brett McGurk, Trump’s special envoy for the global coalition to defeat the Islamic State, told reporters that U.S. troops were going to be in Syria for the foreseeable future. “Nobody is saying that they are going to disappear,” he said of Islamic State fighters. “Nobody is that naive. So we want to stay on the ground and make sure that stability can be maintained in these areas."

Then on Wednesday, senior Trump administration officials told reporters the president had ordered a complete and rapid withdrawal of the military personnel in Syria, estimated at about 2,000. “We have defeated ISIS in Syria, my only reason for being there during the Trump Presidency,” President Trump tweeted.

Suddenly, the entire equation in Syria was reordered. U.S. allies, including Kurdish militias that helped fight the Islamic State, feel abandoned. American rivals in the region, including Iran and Russia, were handed more leverage across the country.

Here’s a look at some of the twists and turns since Trump took office:

November 2016: During the campaign, Trump attacked then-President Barack Obama for his Syria policy, calling him weak and suggesting the United States should avoid getting stuck in a conflict there. “We should stay the hell out of Syria,” Trump tweeted in 2013. As president, Trump promised to bring Americans home quickly.

After taking office, the Trump administration continued to develop plans for a withdrawal. Then something happened to draw the administration further in.

April 2017: After credible accounts that the government of Bashar al-Assad had used chemical weapons against its own people, killing scores including many children, Trump authorized a limited airstrike on a Syrian air base. Trump called Assad’s behavior “reprehensible."

“Tonight, I ordered a targeted military strike on the air base in Syria from where the chemical attack was launched,” Trump told reporters at the time. “It is in this vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons.”

April 2018: As is so often the case with this White House, Trump seemed to reshape years of carefully considered policy with off-the-cuff remarks.

At a speech in Ohio, Trump told a cheering crowd: “We’re knocking the hell out of ISIS.” He also said: “We’ll be coming out of Syria, like, very soon. Let the other people take care of it now.”

A few days later at a news conference, Trump said “it is time” to get out of Syria. “I want to get out. I want to bring our troops back home. I want to start rebuilding our nation,” he told reporters. At that event, Trump also said he believed the Islamic State had been defeated, and that the money spent on the struggle would be better spent at home.

Quickly though, officials began to walk back those statements. The president acquiesced to commanders who said they needed more time to wrap up their mission.

September 2018: Senior military officials told The Washington Post that the president had agreed to a new strategy that “indefinitely extends the military effort” and “launches a major diplomatic push to achieve American objectives.” According to senior aides, the Trump administration had expanded its Syria mission to include pushing out all Iranian military and proxy forces, along with the establishment of a “stable, nonthreatening government acceptable to all Syrians and the international community.”

That policy change came after officials concluded Russia would not help boot Iran.

“The new policy is, we’re no longer pulling out by the end of the year,” James Jeffrey, Secretary of State Mike Pompeo’s representative for Syria engagement, told The Post. “That means we are not in a hurry.” In that interview, Jeffrey confirmed that Trump was supportive of the broader mission.

December 2018: Hours after the surprise announcement of the troop withdrawal, the Pentagon said it was already taking steps to bring out U.S. forces and “transition to the next phase of the campaign” against the Islamic State. But political sparks began in Washington. Even some reliable Trump backers, such as Sen. Lindsey O. Graham (R-S.C.), were dismayed. He said he felt “blindsided” by the decision and decried it as “a disaster in the making.”

“The biggest winners in this are ISIS and Iran,” Graham said.