H & H raises a good question(s).....but finished halfway in the process much like those he mentions without doing so.
...finding ourselves at a bit of a "loose end," we turned our attention to said Dictators and "meddled" on human rights/oil/WMD/whatever grounds, thereby distracting/eliminating the various "managers" from, erm, managing the extremists for us. Is that part of the issue we see today? As I say, genuine question.
The quick answer is easy....he is right.
The harder answer is being able to correctly identify what to disassemble and when the Timeline begins.
I would suggest the origins begin with the European division of ancient lands (as mentioned by others) during Colonial Times and move forward from there.....and end with a dissection of methods used at the nearest end of the process.
When we stuck our latest oar into the mire....we failed to adequately replicate the methods that worked to keep things under control.
Let's ask another question.....exactly when, where, how, and why did we see the rise of radical fundamental Islamism and its associated acts of Terror and Mass Killing.
That is what we are confronting now...today....in our own homelands and shall be doing for the foreseeable future.
Is Putin and his actions the more serious threat than that of Islamic Terrorism or are we placing wrong priorities by the building of the two aircraft carriers and not investing those sums into counter-terror efforts.
We cannot ignore Putin and the Russians....but they are a far more identifiable and conventional foe as compared to the other threat we face.