So an American ship boarded under the orders of a foreign Government while in international waters would be condemned in the US for not allowing the boarders to take charge without a fight? That is interesting.

I said nothing about condemnation. But if you attempt to use deadly force against someone, especially a sovereign military than you should expect deadly force to be returned especially when the military taking action against you is quite obviously using non-lethal force against you. It's the bargain you make in a situation like that. You can attempt to repel the boarders (whether they are justified in boarding you or not) but if you attempts utilize deadly force, then you have in essence asked the boarders to use deadly force against you in return. Thus, they got exactly what they asked for when they used deadly force against their boarders.