I oppose torture because:

1. We lose the moral high ground.

2. We give the enemy recruitment material.

3. We justify the enemy torturing our guys.

4. The enemy will fight much harder if they know that they'll get tortured if captured. They will be far less likely to surrender / capitulate.

5. Winning the peace after victory will be much harder.

6. The intelligence you get is likely to be crap anyway.