The current administration is involved in a frantic round of diplomacy in response to the fall of Assad and the rise to power of Hayat Tahrir al-Sham (HTS), a Syrian Islamist armed group that the US designates as a terrorist organisation. 

I'm writing this onboard Secretary of State Antony Blinken's plane, as he shuttles between Jordan and Turkey trying to get key Arab and Muslim countries in the region to back a set of conditions Washington is placing on recognising a future Syrian government. 

The US says it must be transparent and inclusive, must not be a "base for terrorism", cannot threaten Syria's neighbours, and must destroy any chemical and biological weapons stocks. 

For Mike Waltz, Trump's nominee for national security adviser, who has yet to be confirmed, there is one guiding principle to his foreign policy.

"President Trump was elected with an overwhelming mandate to not get the United States dug into any more Middle Eastern wars," he told Fox News this week.

He went on to list America's "core interests" there as the Islamic State (IS) group, Israel and "our Gulf Arab allies".

Waltz's comments were a neat summary of the Trump view of Syria as a small jigsaw piece in his bigger regional policy puzzle. 

His goals are to ensure that remnants of IS remain contained and to see that a future government in Damascus can't threaten Washington's most important regional ally, Israel.

Trump is also focused on what he sees as the biggest prize: a historic diplomatic and trade deal to normalise relations between Israel and Saudi Arabia, which he believes would further weaken and humiliate Iran. 

The rest, Trump believes, is Syria's "mess" to work out.