Most likely to be blamed on the unnamed "terrorists" again, as a number of recent attacks in Russia. Strangely enough, Russia does not react until now, but seems those "terrorists" will not stop until they or their masters get the desired reaction. Whether it will be intervention in Middle East where "the terrorists hide", or something else. Chechnya is already under full control and there aren't so many terrorists left free there.
Belarus is a member of the Russia-Belarus union, an attempt to revive the USSR.