Dist of Columbia
Rules state that "At the start of each round, the player must check the battle tracks to see whether or not a land battle has been won."
It seems odd that if the Roman player started a land battle showing +1 strength in the Roman's favor, that it would then be won by Rome at the beginning of the Carthaginian player's round before Carthage could respond. In this way all battles would be one sided? No tug of war to the battles. Is this just poor wording? Should it read "At the beginning of the attacking player's round....?"
To add to what Dan said-- At the start of the Carthage round, Carthage checks to see if Carthage won. It doesn't matter at this point if Rome is in a winning position. If Carthage hasn't won, move on to actions.
If Carthage is in a losing position it has two actions to get the marker back to the neutral or blue positions or Carthage will lose at the start of Rome's round.
So it doesn't matter if it's the attacking or defending player's round. It only matters if the player whose round is beginning is in a winning position on the battle track. This makes all the battles a total tug of war.