WASHINGTON -- Two years into Donald Trump's presidency, his allies in Congress are quietly trying to influence and even reshape his "America First" foreign policy agenda.
The Republican-led Senate is reasserting itself as a check on Trump's instincts, while individual GOP lawmakers are seeking sway — defense hawks vying with noninterventionists — over policy in the Middle East, Latin America and beyond.
Within one recent week, Florida Sen. Marco Rubio led a group of lawmakers to the White House encouraging Trump to back Venezuelan opposition leader Juan Guaido as the interim president. Trump tweeted his support. Days earlier, Kentucky Sen. Rand Paul was at the White House reinforcing Trump's plan to withdraw U.S. troops from Syria and Afghanistan.
The result can often seem like a foreign policy in flux, zigzagging from bold pronouncements to more measured actions as "a number of different voices on the Hill are trying to put their imprint on the policy," said Brian Katulis, a former Clinton administration national security adviser now at the Center for American Progress.
"It's sort of this great improvisation directed by the president of the United States, that doesn't really follow any of the notes or sheets of music," Katulis said. "Like he's making things up as he goes along."
Setting the tone in the Senate, the first bill of the new year reaffirms sanctions on Syrian officials involved in war crimes and soon will include an amendment taking the unusual step of signaling opposition to Trump's plan to withdraw troops from Syria and Afghanistan.
Pushed forward by Senate Majority Leader Mitch McConnell of Kentucky, the legislation also is driving a political wedge dividing Democrats, particularly those running for president in 2020, over the troop withdrawal and a separate provision supporting Israel.
Rubio, who led the floor debate and is emerging as a foreign policy leader, said the vote was about ensuring that senators and the legislative branch "play our rightful role in the setting of American foreign policy."
"It is important that the Senate be on the right side of this issue so that we can hope to influence future actions and policies before they are taken, and we can help change them once they have been taken in places headed in the wrong direction," Rubio said.
Next up, McConnell is promising a debate on the importance of NATO, as Trump re-evaluates the U.S.'s long-standing commitment to its allies in Europe.
"NATO deserves the Senate's support," McConnell said.
Danielle Pletka, a senior vice president at the conservative American Enterprise Institute, said lawmakers are doing exactly what they should — asserting themselves as a separate but equal branch of government that has been largely dormant on foreign policy.
"It's abnormal for members of Congress to be as disengaged as they have been," she said. "This is a return to normal."
Trump rode a populist wave to the White House with an "America First" approach focused on rebuilding the United States and bringing U.S. troops home, rather than funding wars overseas.
It's an instinct that fits more neatly into Paul's noninterventionist wing, which rose to prominence with the tea party, rather than the worldview of traditional foreign policy conservatives such as McConnell, Rubio and Sen. Lindsey Graham of South Carolina.
Gaveling that divide is the new chairman of the Senate Foreign Relations Committee, GOP Sen. Jim Risch of Idaho, who took over from outspoken Trump critic Bob Corker of Tennessee, who retired.
Risch said "don't read too much into" the first vote of the new Congress, saying lawmakers aren't necessarily sending any message or asserting themselves any more than usual.
"I think the Congress recognizes when it comes to construction and implementation of foreign policy, the Founding Fathers gave both the legislative branch and the executive branch a role," he said. "And it isn't really clearly defined as to who's got the upper hand."
Unlike the first years of the administration, when Republicans tested how publicly to oppose the president, often with mixed results, senators now seem to prefer softer diplomacy and private meetings to shape his policies.
Paul said after meeting with Trump in mid-January that no other president in recent history has taken steps as bold as Trump to disentangle the United States from wars.
"We live for the day that somebody will stand up and say, 'I'm going to change history,'" Paul told reporters at the time. "You're really seeing one of the extraordinary things."
A week later, Rubio and a group of lawmakers from Florida were at the White House urging Trump to support the opposition leader in Venezuela over embattled President Nicholas Maduro.
Florida GOP Sen. Rick Scott said the president was in listening mode and Rep. Mario Diaz-Balart, R-Fla., said the administration has been "very open to speaking to us."
Trump tweeted his support the next day for the South American nation's opposition leader.
As Trump develops his plan to withdraw troops from Syria and now Afghanistan, the conversations continue.
McConnell talks with the president often. Traditional GOP hawks, including Sens. Tom Cotton of Arkansas and Joni Ernst of Iowa, were among a group of House and Senate Republicans who met with Trump at the White House shortly after he announced his decision for the Syria withdrawal.
Ernst told Iowa reporters this past week that she disagreed with his assessment that the Islamic State group had been defeated in Syria, She said she "will continue to do so when I believe what we're getting from the intelligence community is different from what advisers are giving to the president."
Associated Press writer David Pitt in Des Moines, Iowa, contributed to this report.