It looks like we are sending ground troops into Syria, specifically Marines artillery and armored vehicles, which is a significant escalation from the special forces previously in Syria:

The United States, feeling confident enough about its war on the totalitarian Islamic State, has upped the stakes by deploying a detachment of Marine artillery into Syria.

To be sure, U.S. troops are certainly in combat in Syria, although the deployment of artillery is a step further than Special Operations Forces working with local U.S. allies in the country. Commandos often travel in smaller numbers, can move faster and do not need as much security as artillery units.

………

Pentagon officials stated that the deployment of the troops and their 155-millimeter M-777 howitzers, summoned from the 11th Marine Expeditionary Unit, has “been in the works for sometime,” according to The Washington Post.

………

Meanwhile, in a highly visible — and deliberately visible — move, U.S. soldiers riding in Stryker armored vehicles flying American flags drove into the Syrian city of Manbij to prevent a clash between the SDF and the Turkish-backed FSA brigades.

This will not end well.