Killings show ISIS remains a threat in Syria's desert 5 years after losing its caliphate

• ISIS staged attacks that killed scores of Syrian government soldiers in June.
• The ISIS attacks are a sign of the weakness of the Assad regime and the factions fighting it.
• "I do not see ISIS making an important comeback in the near future," a Syria expert said.

The Islamic State terror group may have lost its territorial caliphate, once equal in size to the United Kingdom, years ago, but its militants are still killing soldiers and civilians in the Syrian desert.