You have identified the core problem, because the fundamental question must be -Can the Arabs sort themselves out? It seems to me after more than 100 years of meddling, that the one thing that has not worked is precisely the argument you propose to justify external interference in the Middle East.
One of the reasons why the region has been such a permanent 'problem' in international relations has been the resistance that the Arabs have mounted to external meddling, a resistance far more effective than has been seen in Africa, Asia or Latin America -think of where Vietnam is today compared to say, 1964; across the whole of the Caribbean, rebellious states like Haiti and Cuba are in disarray, the rest, including Grenada, compliant satellites of the American economy (which was their fate anyway). Parts of Africa are now owned by the Chinese, other parts in debt to multi-national corporations plundering their mineral resources, few mount a resistance as clearly as the states as you find in the Middle East.
There is a paradox here, because the modern state is in crisis, yet economic and social change has taken place, and it is this rift between the realities of the lives people lead and the way in which their states are run that is at the root of this crisis.
What is being argued, by Olivier Roy and Gilles Kepel, is that political Islam is actually in decline from a period between the 1960s and the 1980s when it was in the ascendant; that it has failed to deliver what people want, that most younger people are now plugged into a connected globalised world with its films and music and opportunities to be expressive, and have no real interest in chopping people's heads off or forcing women to cover themselves up and stay at home. But this generation is powerless because the Middle Eastern state has always been an overbearing, top-down structure in which a small group of elites -royal families, military cousins- run everything, while handing out food subsidies, above all, jobs to bring a percentage of people into a dependent relationship which it would be against their interests to harm and which protects the state from political change.
Syria ran out of the money and the jobs it could hand out to maintain a compliant population, people wanted more than the state could deliver, but instead of embracing change, as many felt Bashar al-Asad would when he succeeded his father, he became another version of Hafez, convinced that what worked for Baba -the violent suppression of dissent- would work again.
Middle Eastern states have to change; and they will change, but not soon, and not as long as the choices its people make are made on their behalf in Washington DC or Moscow, or Riyadh and Tehran. Raining bombs will kill a lot of people, what problems in actual fact, will it solve?