WASHINGTON — President Bashar al-Assad of Syria, condemned by the Obama administration and much of the West for waging a brutal war of suppression against Islamist opponents in his country, said this week that President-elect Donald J. Trump could be a “natural ally” in the fight against terrorism. The comment underscored the degree to which the new administration’s approach could reverse central tenets of American foreign policy.
In an interview with the Portuguese broadcaster RTP published on Tuesday, Mr. Assad — whom President Obama wants removed from office — welcomed the prospect that Mr. Trump would make good on his campaign promise to focus exclusively on fighting the Islamic State and to align the United States with Russia, a close ally of Mr. Assad’s, in doing so. The Islamic State, also known as ISIS or ISIL, is one of an array of moderate and extremist groups seeking to topple Mr. Assad.
Mr. Assad’s statements — a remarkable shift in tone from a leader who Secretary of State John Kerry has said should be investigated for war crimes along with Russia — highlighted both the complexity of the foreign policy challenges awaiting Mr. Trump and the extent to which he has signaled a break from Mr. Obama’s approach, especially in the Middle East. In Syria, Mr. Trump will inherit an especially tangled set of alliances and trade-offs, a situation that has bedeviled Mr. Obama in a region currently the site of United States military action in support of efforts to contain or destroy the Islamic State.
While allowing that what he called “opposing forces within the administration” could cast doubt on whether Mr. Trump “can deliver on his promises,” Mr. Assad said that “if — if — he fights the terrorists, it is clear that we will be a natural ally, together with the Russians, Iranians and many other countries who want to defeat the terrorists.”
His comments, while cautious, were the latest evidence of a growing expectation among both opponents and allies of the United States that Mr. Trump will reverse Mr. Obama’s policy on Mr. Assad, which lays much of the blame for the Syrian civil war at his feet. A European diplomat said on Wednesday that officials in Germany and Britain are bracing for an American about-face on Mr. Assad, and Arab diplomats expressed a similar worry.
In an interview last week with The Wall Street Journal, Mr. Trump signaled as much, suggesting that once he took office he would drop American support for certain Syrian opposition groups that have been fighting both the Islamic State and the Assad government, and focus solely on bombing the Islamic State. “My attitude was you’re fighting Syria, Syria is fighting ISIS, and you have to get rid of ISIS,” Mr. Trump said.
But foreign policy experts, both Republican and Democratic, say such a move will most likely leave the new president with a very different problem: deciding how to finesse the battleground of the Syrian civil war — which will still be going on — without putting back in place all of the factors that led to the rise of the Islamic State in the first place.
The Islamic State is in retreat regardless of Mr. Trump. The American-backed campaign to retake the last Islamic State stronghold in Iraq — the city of Mosul — is well underway. In Syria, the American-led coalition has been gaining ground on the Islamic State’s stronghold of Raqqa. While Raqqa may not be retaken by Jan. 20 when Mr. Trump is sworn in, Pentagon officials say that Mosul probably will be, and that Raqqa could fall not long after.
But the battleground defeat of the Islamic State is almost the easy part. Mr. Trump’s administration will then have to confront hard choices on the other war in Syria, namely balancing the competing forces of traditional American opponents — Syria, Russia and Iran — with traditional American allies. These include Turkey, a NATO ally, and the Sunni Arab countries, like Saudi Arabia and the United Arab Emirates, who want to arm and bolster groups opposed to the Syrian government.
Mr. Assad, Russia and Iran are not just fighting the Islamic State. They are also fighting any Syrian groups opposed to the government, including ones backed by the United States and the Sunni Arab countries. If Mr. Trump abandons that alliance for the Russia-Syria-Iran axis, he will effectively be strengthening Mr. Assad’s government. That is the same government whose repressive, anti-Sunni policies are blamed by American, European and Arab governments for fueling the rise of the Islamic State and other extremist groups to begin with.
“You might win the battle against ISIS in Raqqa, but you can’t win the overall counterterrorism war, and achieve a favorable balance in the Middle East, unless it’s linked to addressing the civil war with Assad,” said Michael G. Vickers, a former top Pentagon official. “Aligning with Russia, and implicitly with Assad and the Iranians, would be a strategic blunder with our Sunni allies.”
Some Syrian rebel groups, long frustrated that the Obama administration has not given them greater military support, say they are bracing for a complete cessation of American aid, but they express hope that allies like Saudi Arabia and Turkey will continue to supply them, even in defiance of the Tump administration.
Emile Hokayem, a scholar at the International Institute for Strategic Studies, said Mr. Assad had long calculated that, over time, Western countries would either adopt his view that the rebels were all radicalized jihadists, or prioritize fighting terrorist groups over support for the moderate forces challenging Mr. Assad’s rule.
“This was a waiting game par excellence, one perfected by his father and now him, and one that seems to be paying off: give up nothing, feed and survive the chaos, and wait for the others to cave or rethink,” Mr. Hokayem said in an interview.
Mr. Trump’s expressed fondness for deal making could open the door for the return to the United States of Austin Tice, a journalist and former Marine officer who disappeared in Syria in 2012. Mr. Tice is believed to be held by the Syrian government, which has yet to publicly acknowledge that it has him.
But it is doubtful whether Mr. Trump will get a clear pass on Capitol Hill at striking an alliance with Syria and Russia, even from Republicans. Senator John McCain, Republican of Arizona and chairman of the Senate Armed Services Committee, this week called the bombing campaign by President Vladimir V. Putin of Russia and Mr. Assad “barbaric” and warned against any American attempts at reconciliation with Russia.