Vladimir Putin's Excellent Syrian Adventure was all fun and games so long as he was hitting Bashar al-Assad's enemies (which rarely meant Daesh until that group downed a Russian airliner) and those enemies couldn't fire back.
However, Russian pilots had the unfortunate habit of straying into Turkish airspace. This was understandable, as the air space in the war zone was rather tight. But the Turks warned Russia after the last incident that another violation of their airspace would bring about a response.
Today, a Russian jet again strayed into Turkish airspace. According to Turkey and the coalition command in Baghdad, Turkey warned the Russian plane ten times to leave its airspace. The Russians either didn't hear the warnings, or ignored them, at which point Turkey downed the Russian jet. The pilots ejected, but didn't survive. (The details of their deaths are still sketchy, but it seems that Syrian rebels shot them down.)
Mr. Putin, desperate to show that Russia is still an important power aside from its possession of nuclear weapons and a veto on the Security Council, decided to go in militarily to prop up his client Mr. Assad. At the time that he did so, I said that Russia had learned nothing from its adventure in Afghanistan.
It's even worse. NATO warplanes weren't flying over Afghan skies in the 1980s. Syria is even more of a quagmire than Afghanistan, and prone to something Afghanistan wasn't: direct confrontation with NATO air forces.
Mr. Putin calls the downing of his fighter a "stab in the back". But, it was a predictable outcome. Once Russia became involved in the Syrian fighting, it was only a matter of time before an incident like this occurred.
What happens next? I'm not a prognosticator. But a NATO member nation shooting down a Russian jet is not a good development. This is why Ben Carson's casual talk of imposing a no-fly zone over Syria and shooting down Russian jets if they violated it was so insane. I'm not saying this one incident will lead to a wider war; but it's not something to be taken lightly. Here's to hoping cooler heads prevail.