How about this approach...
Pirates are stealing from maritime vessels, so I take it as like an armed robbery. If we're supposed to "not deal or bargain with terrorists," don't pirates fit under that?
Personally I think the navy should take an approach that, causes the least amount of killing without agreeing to the pirate's demands or ransoms, and regaining control of the ship in the shortest amount of time.
If that means killing the pirates, then by all means the navy should go ahead with that. The situation should be dealt with before hostages start getting held at gunpoint.
I also hate the concept of having "rules in war." If we're out to successfully overcome the problem of piracy in Somalia we can't say, wait we're not allowed to do that because it's not allowed.
http://people.howstuffworks.com/rules-of-war.htm
Suprise attacks, false negotiations, flying false flags, wearing enemy combatants' uniforms, ect are all prohibited under the numerous war treaties that the US has signed.
I believe most of these laws should be revoked except for the ones revolving around wounded combatants. The most effective method should be used, you can't successfully win any fight with both of your hands tied behind your back.
Bottom line, If the pirates resist surrender for a prolonged amount of time, anything is fair game including their killing.
While some may say that pirates are victims of the West's failings, its their own faults for not waiting for the UN and other programs to give them aid. If you say, aww the UN is useless, it's only because people like you and the pirates don't believe aid will ever come, so they take matters into their own hands. The UN always needs time to deliberate and act as any bureucracy does, but they will act.
Anyways that's my two cents.
FLAME ON!!!!!!!!!!!!!!!!