I forgot which Rabbi it was, but the point will be the same. There were hoodlums one time in the town of this great Rabbi and they were causing a lot of damage. So he started to pray that they die. His wife told him to pray that they do teshuva instead. So he prayed that they do teshuva, they repented, and that was that. I think we can learn a lot from this story. We should ask Hashem to defeat our enemies by causing them to do teshuva. Hashem could do anything, including changing people. I'm as pro-killing enemies as the next guy, but maybe Hashem is keeping them alive for a reason. Now I know they won't ALL repent (I could just see Achmadinajad ysv doing viduy) but maybe a few here and there. I mean, Hashem hardened Pharoh's heart, so you never know, right?