"I can see how it might start, but I am not sure when or where," Mattis said. "I think that it's very likely in Syria because Iran continues to do its proxy work there through Hezbollah."
Mattis also accused Iran of "bringing advanced weapons for Hezbollah through Syria." He claims that these maneuvers will not be tolerated by the Israelis, who have the Lebanon-based Hezbollah at the top of their enemies list.
"Any site in which we see an Iranian attempt to achieve a military foothold in Syria will be struck. We won't let that happen, regardless of the price," Lieberman said to Elaph, an Arabic news provider.
While Israel is getting stronger on the Iran issue, that leaves the question of United States involvement in the coutry. The Trump administration has always signaled against nation-building in the Middle East, but refuses to leave Syria despite ISIS being largely decimated in the region.