President-elect Donald J. Trump will inherit a dangerous new Middle East crisis in Syria when he assumes office in January. But how he might approach a nation now controlled by rebels with terrorist roots is unclear, and may be decided by fierce competing arguments among advisers and foreign leaders in the months to come.

There are many good reasons to expect Mr. Trump to take a hands-off approach to Syria, which erupted into civil war in 2011. One is Mr. Trump’s apparent disdain for the country, which he has branded a land of “sand and death.”

Mr. Trump has also long railed against broader U.S. efforts to reshape former Middle East dictatorships such as Iraq and Libya, in what he calls America’s “endless wars.” As rebels entered Damascus, Syria’s capital, over the weekend, Mr. Trump posted on social media that the country was “a mess” and that the United States “should have nothing to do with it.”

“This is not our fight. Let it play out. Do not get involved,” Mr. Trump wrote, in all capital letters.

The sentiment was echoed on social media by Vice President-elect JD Vance, a fervent critic of American foreign policy overreach.

Mr. Trump plans to nominate Tulsi Gabbard, a former Democratic congresswoman, as his director of national intelligence. She has spent years arguing that the United States has no business getting involved in Syria’s long-running civil war.