[Blasted Child]

Ok, fair enough. I'm really disappointed that the passengers used violence as a response to the boarding.
But it's still quite interesting...this whole scenario could very well fall back on one of the most honoured and protected american principles - namely the right to protect yourself against trespassing, at virtually any cost.

If this had been another situation, let's say an american non-military vessel on its way to, let's say the Congo, and the ship was suddenly boarded by Angolan coastguard (ok I'm just throwing out stuff here, don't point out if it's unlikely or whatever) noone in their right mind, especially not Americans, would consider it strange or unappropriate or unlawful if the American charity workers used whatever weapons they could find to protect themselves.