Although the Syrian government has also been fighting ISIS and related extremist groups for three years, the US refuses to speak to the Syrians and has warned Assad not to interfere with the coming US attack on sovereign Syrian territory
President Obama promised that airstrikes alone would "degrade and destroy" ISIS, telling the US military in a speech last week that:
"The American forces that have been deployed to Iraq do not and will not have a combat mission… I will not commit you and the rest of our armed forces to fighting another ground war in Iraq."
But of course any US troops sent into a war zone are "combat" troops. And more are on their way.