Belarus continues to complain about the build-up of Ukrainian forces on its border, now reportedly with rockets and other equipment. Given the limits of Ukrainian forces generally, it is highly unlikely that Ukraine is preparing to invade Belarus. Kremlin spokesman Dmitriy Peskov has already said that Russia would react if Ukraine made a move against the borders of Belarus.
Konstantin Sivkov, a doctor of military sciences at the Russian Academy of Rocket and Artillery Sciences posits the hypothesis that Ukraine would like to provoke a reaction from Belarus which would give them an opportunity to invite NATO forces into the war.
