Have you read what I posted here about ISIS? It’s not that simple. ISIS is not just bunch of black clad imbeciles driving Toyota Hiluxes roaming the Syrian desert. ISIS is the paramilitary wing sunni salafi islam - Saudi Arabia and Qatar to be precise.
In the grand scheme of things, most of those ISIS fighters are foreigners and salafi cannon fodder (a shocking number of them are French and Belgian). The Saudis can always let the majority of them get killed as they’re a hindrance, pull back the remaining operatives and resurrect them as “rebranded” ISIS at a time and place of their choosing.
Naturally, this would allow The Donald to declare “victory”. So the litmus test is the relationship between Trump’s administration and the House of Saud. If he continues the pro-Saudi US policy then ISIS cannot be beaten no matter how many sunni retards die in Syria and Western Iraq.
In case you haven’t noticed “rebranded” Al Qaeda is fighting in Syria (now they’re Al-Nusra). You know, the 9/11 guys. And they’re not wearing robes anymore, but desert pattern uniforms, US made body armor, kevlar helmets and MLRSes provided by the Gulf dictatorhips.