I have discussed the present situation in Syria and Iraq with Larry Johnson. We speak daily. IMO it is true that US Rules of Engagement on air attacks have recently been loosened and that US ground advisors are pressing their luck more at present than they had and this has resulted in more US casualties. IMO this is the cost of doing business.
There are also offensive actions underway in the western suburbs of Aleppo City, on the road to Palmyra and in the greater Damascus area. And of course Euphrates Shield is a major difficulty for IS.
IMO none of these actions are key to the outcome for the Syrian Government. The continued occupation of Idlib Province by the rebels (mostly jihadis connected to AQ) allows a gradual consolidation of jihadi power in that province of essential Syria. IMO so long as that province is in rebel hands the government will never be able to plausibly claim to control Syria. pl