"Should all combatants be treated as POW's? They do not seem to recognize, nor be bound by the Geneva Conventions."

Yes and it doesn't matter what the enemy recognizes.

ter.ror.ism [ter-uh-riz-uhm]

–noun 1. the use of violence and threats to intimidate or coerce, esp. for political purposes.
2. the state of fear and submission produced by terrorism or terrorization.
3. a terroristic method of governing or of resisting a government.

For us to ignore the Geneva Conventions and the "decider" to choose who is and isn't a terrorist, AKA Enemy Combatant, without a trial is a win for terrorists....see above definition. It's pretty much agreed that the only true way to defeat terrorism is to win hearts and minds lest we create more.