Whilst not disagreeing with the overall principle of "just" wars to prevent genocide etc. The practical problem that we just aren't very good at them, remains.
Yes Saddam Hussain was a very nasty man who was brutal to some of his own population. But is the life of the average Iraqi shop keeper or Cobbler better now?
The Taliban were not nice, but they were the church of England doing jumble sales and cake bakes compared to ISIS.
Would it have been better, rather than encouraging the "Arab spring" to assist in stopping it.
Is Egypt any better under a military government than under the old regime?
What about Libya? It's pretty much anarchy. Would Gadhafi be blowing up ancient ruins or flooding the black market with the contents of his armoury. Hi might have still sold a few weapons on the side but nothing like the free for all looting that happened after his fall.
Syria is a hot mess right now. If there was a parallel universe where the West hadn't egged on the Syrian opposition and instead had said "OK Assad, crack down but keep the violence to the absolute minimum" - would there be fewer or greater deaths? Would the living conditions of Syrians be better or worse. Yes a few hundred political protesters might have been tortured or shot during crack downs (and I'm not condoning that) but is that a price worth paying compared to the tens of thousands of deaths, the torture, the refugee crisis which is causing problems outside the region?
In short, it think it's hard to make the case that, in general, military action causes less suffering (although there are some case where it has) or even that it is cheaper. Imagine what could have been done to the Asia, Middle East and Africa if the billions spent on wars had been ploughed into development of infrastructure, education, healthcare.
