WASHINGTON, D.C. — Less than a week after controversial strategist Steve Bannon left the White House, President Donald Trump is already signaling a shift toward a more traditional Republican foreign policy.

The president indicated late Monday that he would extend America’s commitment in Afghanistan, breaking a campaign promise and siding with military commanders over the wishes of his nationalist advisers and supporters who flocked to Trump’s “America First,” anti-interventionist message.

He is now the third president to pour resources into what is now America’s longest war.

“As an American citizen who is wondering how we’re going to win this situation, I feel a lot better knowing that the advice of those guys was taken over a handful of bloggers,” said Scott Jennings, a former special assistant to President George W. Bush who has been approached for work in the Trump administration.

Before he entered politics, Trump was dependably critical of the handling and cost of the war that the United States launched in response to the terrorist attacks in New York and Washington on Sept. 11, 2001. He launched his presidential campaign on a nationalist message and promised to get out and stay out of foreign conflicts.

Indeed, Trump often talked about knowing more than U.S. generals.

But since entering office, his position has shifted dramatically. He launched missile strikes against the Syrian military in April, promised to unleash “fury and fire” on North Korea and threatened to send U.S. troops into Venezuela.

On Afghanistan, Trump ultimately demurred and said he would follow the advice of his military experts and his Cabinet stacked with generals.

Trump did not offer specifics on Monday, but House Speaker Paul Ryan on CNN said he had been briefed on a plan that could see the Pentagon sending as many as 3,900 additional troops into the war zone. Ryan was supportive.

“Trump did … exactly the right thing in insisting his new team — who are all extraordinarily experienced — go back and review what we tried to accomplish and why did it not succeed,” said Newt Gingrich, the former House speaker and an informal adviser to Trump.

The shift reflects the difference between someone running for president and someone being president, say military experts, who praised Trump for listening to national security adviser H.R. McMaster and Defense Secretary James Mattis, as well as Chief of Staff John Kelly, another retired general.

But not everyone agrees. Bannon, a driving force behind Trump’s nationalist campaign, wanted Trump to refuse the generals’ advice. He was sidelined during a critical decision-making session on the next steps in Afghanistan the same day news broke that he was ousted from the White House.

“Bannon’s influence was slipping over many months on foreign policy. From the start, Bannon wanted to dismantle a lot of alliances and reduce America’s role in the world and Trump was moving toward Mattis and McMaster and Kelly and then (Secretary of State Rex) Tillerson and (U.S. Ambassador to the United Nations Nikki) Haley,” said Michael O’Hanlon, a long-time military expert and senior fellow at the Brookings Institution.

Now that Bannon has returned to leading Breitbart, that far-right website has turned from intensely supportive to critical of the president.

“The president risks fumbling into the kind of intractable conflict he specifically promised his voters he would avoid,” wrote Breitbart’s Joel B. Pollak before Trump’s announcement.

More mainstream Republican voices, however, were already cheering what they saw as the start of what they hoped would be a move toward normalcy for a White House that has been chaotic and erratic.

“Instead of making policy from the hip, they’re making policy as you would expect the president to do it. For everybody out there who is wanting to be able to say ‘yes, the presidency is under control on these serious matters,’ this is a great night,” Jennings said.

There are now 8,400 American troops on the ground in Afghanistan. Last year, former President Barack Obama withdrew 1,400 troops, but the security situation failed to improve; it worsened.

“There is always this presumption that leaving must be the goal,” O’Hanlon said. “What we should think about instead is a strategy of success and if that means an indefinite duration of a modest U.S. troop presence in a part of the world that is important to our security, then that to me is the correct standard.”

James Jeffrey, a former U.S. ambassador to Iraq and Turkey who also served as deputy national security adviser in the George W. Bush administration, pointed to U.S. policy in Colombia, which leans on a smaller force, as a potential model for Afghanistan.

“There is still in the think-tank community, in the media, buried in the State Department, in USAID, and most importantly in the military — underline that — there is still a strong view of nation building, state building, hearts and minds,” Jeffrey said. “They’ve drank the Kool-Aid.”

Jeffrey said the attention needs to be less on nation building and more zeroed in on fighting counterterrorism and sufficient stability to keep the United States and allies safe and able to operate.