The US has 2,000 troops in Syria backing Kurdish-led forces to contain ISIS militants.The Trump admin is weighing withdrawing these forces, and the Russian military is losing its access."Russia now hangs on by its fingertips," a Syria expert told BI.Syria has been one of the world's most complex proxy fights since its civil war broke out in 2011, but who holds power and where is now shifting rapidly.The biggest change came from the dramatic toppling of Bashar al-Assad's regime in December. It was driven out by the Islamist group Hayat Tahrir al-Sham, who are no friends of Russia or Iran.HTS holds territory from Aleppo in the northwest to Damascus, the seat of the Assad regime. But Syria remains fractured by competing armies. Turkish forces and militants it backs hold pockets near its northern border. The US-partnered Syrian Democratic Forces occupy the large triangle of northeastern Syria, an area that has oilfields and prison camps holding ISIS fighters. Russia is reducing its military footprint as Israel seizes new positions near the Golan Heights. But the newest question mark is the US.The US has 2,000 troops in Syria backing the Kurdish-led SDF to contain ISIS. It also controls the strategically located al-Tanf base in southern Syria. But the longevity of those deployments is unclear. The Department of Defense is reportedly drafting contingency plans to withdraw all troops should President Donald Trump order it."Presently, the HTS-led government is seeking to create the conditions for a US withdrawal from the country that would undermine the SDF coalition, which represents an impediment to the emerging regime's ability to control all of the country," Nicholas Heras, senior director of strategy and innovation at the New Lines Institute, told Business Insider.US forces in Syria safeguard oilfields and assist the SDF in strikes to defeat remnants of ISIS. These forces are potential leverage that Trump risks losing if he withdraws them before talks with the new government under interim president Ahmed al-Sharaa."It seems likely that the Trump administration will keep troops in Syria over the short term and speak about a step-by-step policy of loosening sanctions based on President Sharaa's willingness to develop a constitution and move toward a representative government that does not threaten its neighbors," Joshua Landis, Director of the Centre of Middle East Studies and the Farzaneh Family Center for Iranian and Persian Gulf Studies at the University of Oklahoma, told BI.The easier chip in bargaining could be the US base at al-Tanf in Syria's southern desert. Controlled by the US-allied, anti-ISIS Syrian Free Army group, the base is situated near the Jordanian border and the important Baghdad-Damascus highway. The US enforced a 34-mile de-confliction zone around al-Tanf which Iranian-backed forces and Assad's regime weren't allowed to access."The US presence at al-Tanf was pretty dubious before Assad fell and it serves no discernible purpose now, except possibly as a point of leverage vis--vis the new Damascus government," Aron Lund, Middle East analyst with the Swedish Defence Research Agency and fellow with Century International, told BI. "So, al-Tanf could be a place they'll withdraw from first, perhaps after getting some little thing in return from Sharaa's government."The SDF-controlled regions present a "thornier issue" with much higher stakes. The Kurds guard prisons with thousands of ISIS fighters, but they'd be hard-pressed to maintain these faced with a major offensive by a rival. While HTS has not attacked the SDF, the Turkish-backed militias have done so repeatedly since late 2024."There are some real political risks involved, related to an ISIS revival and the fate of Kurdish groups in that area," Lund said. "Even Trump could perhaps be persuaded that these things are worth negotiating over if only to limit the fallout before withdrawing."Israel expanded its presence along the Golan Heights as Assad's regime collapsed, seizing Mount Hermon. Satellite images show it is building bases there."Israel does not trust the HTS-led government and the Israeli posture suggests that Jerusalem could play a strong role in Syrian affairs for years to come," Heras said. Russian airlifters ferried out troops and armored vehicles from Khmeimim Air Base in December. Izzettin Kasim/Anadolu via Getty Images The outside power that stands the most to gain is Turkey. Ahead of his recent visit to Turkey, reports indicated Sharaa would discuss Turkey potentially establishing bases in Syria's central desert region."Turkey already has a forward operating military presence in northwest Syria, and it is unlikely that it will withdraw its forces from the country in the near future," Heras said. "The HTS-led government wants to leverage Turkey to have a patron state to support the development of its security forces."Russia, by contrast, stands to lose the most. Syria canceled an Assad-era contract with Russia to manage Tartus naval base but Syria's defense minister also said it might let Russia keep this port and the Hmeimim airbase "if we get benefits for Syria.""Russia now hangs on by its fingertips, but we'll see how that turns out," Lund said. "In five years, they could still have Tartus, perhaps also Hmeimim."Moscow has had access to Tartus since 1971. Today, these bases are essential to supporting Russian military and mercenary operations across the Middle East and Africa."The new Syrian government is obviously no friend of the Russians. It needs to be mindful of the views of its political base, which is made up of ex-rebel factions that hate Putin almost as much as they hate Assad," Lund said. He noted that Russia still has "important leverage" over Syria. Rebuilding the Syrian military without Russian arms could prove challenging, even if Syria aims to have Turkey replace Russia's traditional role as its main arms supplier."There's so much legacy Soviet and Russian equipment and training, you can't just throw all that out," Lund said.Syria's new rulers have little to fear from Russia since the days of Russia relentlessly bombing HTS's Idlib stronghold in support of Assad are gone."The Russian bases are there at their mercy, and they seem fairly harmless for the new government," Lund said."Letting them stay could even provide a point of leverage."Paul Iddon is a freelance journalist and columnist who writes about Middle East developments, military affairs, politics, and history. His articles have appeared in a variety of publications focused on the region.