Unless Russian forces are defeated in Ukraine or withdrawn by new Kremlin rulers, Moscow might assault other post-Soviet neighbors. The West may face limits on the extent to which it could help them thwart such attacks.
Forty years ago, Russia used a major military exercise in part to scare Poland's communist leaders into cracking down on protesters. A similar Russian exercise now could be aimed in part at pressuring Belarus. If so, the West could respond in several ways.
In September, President Vladimir Putin signaled that Russia was throwing its weight behind embattled Belarusian President Alexander Lukashenko. But any move to enforce Putin's will in Belarus could invite tougher Western sanctions and scare investors. This would exacerbate problems facing Russia's flagging economy.
Analysts and military leaders have concerns that Russia will use the Zapad 2017 exercise in Belarus as a smokescreen to put personnel and equipment in place, and keep it there. But the deep ties and history of cooperation between the two states make the chances of that happening unlikely.
Public demonstrations in Minsk and across Russia hint that winds of political change and disillusionment with stagnation and corruption may be reaching both countries. Their leaders will blame the West, try to ride out the protests and, despite differences, will likely stick together.