Mikhail Barabanov in Moscow Defense Brief:

Russia holds the Zapad drills along its western borders once every four years; the previous such event took place in 2013. This year, however, the reaction from some of Russia’s neighbors to the west has been nothing short of hysterical.
[…]
For all the Western concerns, the scenario of the main phase of the drills was purely defensive, and focused on defending an allied state (Belarus) from hostile actions and then a direct invasion by the West. In that sense, the scenario was fully in line with the Putin administration’s perception of the domestic and external threats facing Russia. The exercise was a fairly typical reflection of how Russia believes it should act in the former Soviet republics to protect its “sphere of interests” from any encroachment by foreigners. It did not imply any major military operations beyond the borders of the former Soviet Union. As with the famous “Gerasimov Doctrine” (which reflects Russian views of how the West operates, but which Western commentators choose to interpret as Russia’s own preferred course of action), the [Zapad] 2017 drills were not a simulation of a Russian act of aggression. Rather, they reflected the growing concern in the Russian military-political leadership about increasingly blatant Western meddling in former Soviet republics.

Gee, I wonder what caused the former Soviet republics of Estonia, Latvia, and Lithuania to become so hysterical.