A convoy of US military vehicles on patrol in Syria this week came upon a crowd of pro-regime protesters. They were standing near a checkpoint just outside Qamishli. The checkpoint has been there before, but this time voices were raised, a protester tore a US flag from a vehicle and men shot at the Americans with AK-47s. The US returned fire and killed one assailant. The Russians came to help sort things out.The incident illustrates the complex and tenuous role of the US in parts of Syria now. The US partnered with the Syrian Democratic Forces. However in October 2019 the US opened the way for a Turkish invasion of eastern Syria that killed hundreds of fighters who had previously been working with the US and led to ethnic cleansing and atrocities against Kurds who had trusted Washington. Even though the US tried to salvage this by remaining near oil wells in some areas and continuing to help the SDF fight ISIS, the situation has changed. Now Syrians in eastern Syria near the Turkish border have put their faith in the regime and Russia. They don’t want Turkish airstrikes to drive them from their homes or for their family members to end up like Hevrin Khalaf, an unarmed woman beaten and murdered by Turkish-backed jihadists in October 2019. They are wary of US commitments. That has also emboldened pro-regime elements. Syria’s regime, weak and undermanned, has sent officials to try to encourage Arab tribes to oppose the US. The Syrian regime wants to test the Americans. The Russians want to play moderate peace broker, but quietly want to humiliate the US and get the US to leave.It is in everyone’s interest that no blood be shed. But the Syrian protesters decided to interdict the Americans. They sense the power dynamics have changed. That is why they grabbed a US flag off a vehicle and stoned the American column. They fired with impunity at the US vehicles. The Russians stood in the background and watched. People in that area of Syria have also thrown stones at Turkish patrols while Russia watches. Russia is using soft power to slowly win over the locals. Empowered by the Syrian regime offensive in Idlib, there is a feeling the US can be challenged. The challenge won’t come from Kurdish areas. Kurds are disappointed the US has abandoned them along the border, but they fundamentally prefer the US to the Syrian regime or more ethnic-cleansing at the hands of Ankara. Tens of thousands who fled the Turkish invasion are still in cold tents.The challenge will come from the regime trying to push Arab tribes to challenge the US and from Russia stirring up locals. It may even come from ISIS elements and some Syrian rebel elements allied to Turkey. The US now faces a challenge. Its mandate is to fight ISIS. Officially the US wants the Iranians to leave also. And the US wants the oil so it can enable the SDF to pay to house ISIS detainees. This is cynical policy at its best and mission creep. Iran is also watching closely. Along with Russia it would like to entice parts of the SDF back to Damascus. It wants to send its Iraqi-based militias over the border into Syria, as it has already done in the Euphrates valley.The incident in Khurbet Amo, the small village near Qamishli, likely heralds worse to come for the US. The US has cool heads on the ground. The soldiers were professional and calm. But faced with AK-47s shooting at them, the US will have to choose to stop driving on certain roads or retaliate.