I would say that a ground campaign would defeat IS in Syria and Iraq. I cannot be bothered to dig for a definite source for that, but USA, EU military is vastly better than IS and I don't want to waste my time arguing with anyone who thinks that an America/EU/Russian alliance would lose a ground war against IS in Iraq and Syria.
So IS would be left as a guerilla operation in that part of the world, rather than a fully fledged state. They would still kill people, but guerilla methods are less effective than what you can do with full control.
The downside is that the civilized world is bad at nationbuilding - we failed in Afghanistan and to some extent in Iraq. Obviously that would leave an opening for IS to come back again in 25 years, like the Taliban are probably going to in Afghanistan.
But this debate has already progressed beyond the article in the OP.
Yes US/EU troops are superior but as afghanistan and iraq showed, simply having those troops in the country does not solve your problems. Military victory, in the sense that a nominally friendly government ends up in control can be achieved without boots on the ground, it's far easier for friendly groups to win with air support and supplies but you have to avoid public perception that the new state is just a puppet.
Here's my op-ed that uses long-term orientation, probabilistic thinking, numeracy, consider the alternative, reaching our actual goals, avoiding intuitive emotional reactions and attention bias, and other rationality techniques to suggest more rational responses to the Paris attacks and the ISIS threat. It's published in the Sunday edition of The Plain Dealer, a major newspaper (16th in the US). This is part of my broader project, Intentional Insights, of conveying rational thinking, including about politics, to a broad audience to raise the sanity waterline.