Only a few months ago, it looked as though the seven-year war in Syria might finally be coming to an end. ISIS was all but defeated, its self-declared caliphate in ruins, and the forces of Syrian dictator Bashar al-Assad—with support from Iran and Russia—were mopping up the last remaining rebel strongholds. But rather than winding down, what was largely a conflict between rival Syrian factions has instead evolved into something far more complicated and potentially dangerous: a clash of great powers. (See Talking Points.) The past month alone has seen a dizzying series of events. Turkey sent troops and tanks into northwestern Syria to root out Syrian Kurdish fighters, pitting Turkey against its NATO ally the U.S., which views the Kurds as key assets in the fight against jihadist terrorism. (See Best Columns: International.) In the east, the U.S. killed and wounded scores of Russian mercenaries fighting for Assad after they attacked a Kurdish-American base. And in the south, Israel bombed Iranian, Syrian, and Hezbollah bases after an Iranian drone entered Israeli airspace; a Syrian missile downed an Israeli fighter jet during the operation.
With so many competing conflicts and geopolitical interests, the risk of accidents and escalation in Syria is high. You need only look back at the 20th century to see how entangling alliances can cause a seemingly local event to spiral into an international crisis: When Slav nationalist Gavrilo Princip assassinated Austrian Archduke Franz Ferdinand in Sarajevo in 1914, he had no idea his gunshots would suck Germany, Russia, France, Britain, and the rest of the globe into World War I. Of course, neither the U.S. nor Russia or any of the other major powers would rationally want to get into a shooting war with each other, and so far all sides have tried to play down any direct clashes. But war, as history has shown us time and time again, is often an irrational affair.