Who will strike first in the south of Ukraine? [COMMENT]

Over the past week, Russian military vehicles have been reported in the Mariupol-Berdyansk-Melitopol-Nova Kakhovka regions. Moscow is besides to shift forces from the east Military territory to Crimea to the confederate front (including a pontoon-bridge unit and airborne troops). Much is said about a possible offensive by Ukrainians in the south. In this test of strength, who will strike first?