His [Obama's] “red line” about chemical weapons turned out to be more like a penciled suggestion. His rejection of the proposal by Hillary Rodham Clinton and David Petraeus to arm moderate Syrian factions tragically empowered both the Islamic State in Iraq and Syria, or ISIS, and President Bashar al-Assad of Syria.Nick is rolling out the classic circular thinking of American military adventures: if war works then that shows that war is awesome and should be done more often. If war doesn't work (as it didn't in Iraq) then that means that what we need is more war. In short war can never fail to improve things, it can only be failed by presidents that don't do it enough or do it well enough.
Hence the idea that giving more weapons to various Syrian factions would have automatically made things better that Nick cites. There's no evidence of this at all in the real world, for example nobody has ever even suggested giving the Syrian rebels the weapons they would actually need to turn the tide of battle, that is sophisticated anti-aircraft and anti-tank missiles. And rightly so! In Ukraine rebels used such weapons to shoot down a Malaysian jet liner recently. In fact the whole reason ISIS is so powerful right now is they were able to capture a huge amount of weapons this summer that we supplied the Iraqi Army with!
But in Nick's military adventure world this contention proves itself. Since things are bad and we didn't give weapons to Islamic extremists not named ISIS (which is basically what a lot of the "moderates" are) Obama made a mistake, because weapons would automatically have made things better. And indeed in an alternative universe where we did give them weapons and things didn't get better Nick could say, "Obama didn't give enough weapons soon enough!" Or whatever. Likewise nobody thinks the bombing proposed by Obama last year would have ended the war, but again it was a failure because we didn't bomb and bad things happened.
In short, this is a bizarre way to think about the world. Unfortunately it's a pretty popular in our foreign policy establishment.