The signs are multiplying that Vladimir Putin’s powers of coercion are rapidly fading, and his chief instruments of regional leverage are dissolving. Not only have Ukrainian drones put Russian forces on their heels in the two countries’ long-running conflict, but they are also threatening to tear apart the Collective Security Treaty Organization (CSTO), Moscow’s version of NATO. Meanwhile, the Kremlin’s failure to prevent the reelection of Putin’s nemesis in Armenia, Prime Minister Nikol Pashinyan, is helping to expose…