I think Mr. Johnson is correct that the US is spending money to train and arm insurgents because the goal of US policy has not been to eliminate ISIS but to eliminate Assad. It is only when ISIS threatened far more than Syria but the whole region and committed some barbarous acts against Americans and Europeans that ISIS became the target. While such barbarism was being inflicted on Syrians we seemed not to notice.
If the United States wanted to defeat ISIS , it could have joined Assad in fighting it. That is still true today but the US would rather just change its emphasis by fighting both Assad and ISIS, which will not not succeed and will extend the killing and destruction even further into the future.
"War is not the answer," said Dr. King on April 4, 1967. That statement holds true today.
Just remember, all of those earlier moderate Syrian rebels that the CIA, Saudi's, Jordanian's, Kuwaiti's Qatari's, Israeli's and Brits paid, armed and trained, turned out to be a bunch of foreign jihadist's that morphed into the Islamic State and al-Nusra Front! So, where in the hell is this current batch of moderate Syrians coming from Slick Oily?