My friend and I we’re playing in a rather heated revised game and ran into a rules question during the combat phase.  I was playing Axis and was on the offensive.  The situation was that I had control of Caucuses and a 2nd force in Eastern Europe.  He had an army in Russia and a 2nd army in West Russia.  During combat I committed forces to West Russia and the result was that it became an unoccupied hostile territory.  I then tried to attack Russia with my forces in Caucuses and some tanks that I had held out of the first battle in Eastern Europe.  He claims that I cannot use the tanks “because all combat takes place at the same time” and that I cannot cross his territory b/c it was occupied at the start of the combat phase.  I believe that the combat phase is a series of sequenced attacks and the attacker chooses the order of the attacks.  That according to the rules each attack is resolved completely before the next attack occurs. Since the first battle was resolved the tank should be able to blitz and join then next battle in Russia while claiming the unoccupied hostile territory.  We’ve read the LHTR  and have been unable  to  resolve this.  Could anyone please assist us that is neutral in this.