Justaminute: I don't agree with you. As some of you may know I have quite an agressive style. When I attack I use the fact that my opponent cannot move back. For example when I move a piece of the same strength right where my opponent's piece came from. When my opponent can endlessly move back and forth to escape there are several ways of attacking I can't use anymore. Like when the opponent moves between 2 bombs, now it takes 2 moves before this player can move out again. Also if both players keep moving back and forth the game ends in a draw. This will happen a lot.
I think this rule is one of the strong features of espionage. Changing this in an added new version would be very confusing.