"The US pulling out would be the absolute best thing for peace in Syria. The Syrians along with their allies should decide what happens to these groups," McAdams stated. "Understanding and knowing that the US would no longer back them will force them to make some difficult decisions on their own. And I think you will see many more villages, larger villages finding a way to surrender."
McAdams noted that the militants in Aleppo have already been laying down weapons.
"We are actually seeing that in some places around Aleppo, but you will see some kind of negotiated surrender with the extremists, with the terrorists, with the people who by means of violence seek to overthrow their country," McAdams explained. "A lot of them will give up their arms. Some of them may decide to fight to the death."
With the presidential elections in the United States coming up in November, McAdams thinks that the US pullout from Syria is unlikely to happen right after the elections because both major party candidates are essentially interventionist.
McAdams also stated that the conflict in Syria would continue to smolder if the United States does not change its views on strategy of regime change.
Clinton and Trump may approach the Syria problem differently, he explained, adding that a Trump administration can put some 10,000 troops on the ground, while Clinton may "ramp up the drones and start a war with Russia."
Syria has been mired in civil war since 2011, with so-called moderate opposition factions as well as extremist groups like the Islamic State fighting the Syrian Army to topple the legitimate government of President Bashar Assad. The United States has been supporting the allegedly moderate opposition forces in Syria, while Russia has been supporting Syria's legitimate authorities.
On September 9, Russian Foreign Minister Sergey Lavrov and US Secretary of State John Kerry announced a ceasefire in Syria that took effect three days later. The ceasefire unraveled, however, after a September 17 US airstrike on Syrian troops and the government’s subsequent offensive against terrorist positions in the city of Aleppo.
Fighting has been continuing in Aleppo during most of the five-year Syrian conflict. The Russian and Syrian governments agreed to stop airstrikes on Islamist fighters controlling parts of the city starting on Thursday. The humanitarian pause was later extended into Friday afternoon.