Speaking less in the hypothetical, your references to the following--"American lives are lost!", "soldiers are dead!", "police are threatened!"--present a far less difficult question to answer. Frankly speaking, a government's primary job is to protect the people under its watch. This would naturally extend to the people who enforce this basic premise--soldiers defending the nation's "interests" abroad, police maintaining order at home--in the sense that they carry a special status in the government's eyes. If a government can't protect its own citizens, what good is it? And if a government is seeing the people it tasked with carrying out its primary responsibilities dying, then that is symbolic of a government's failure towards its primary responsibility. Obviously, American lives matter more to an American government, and the same principle should apply to any government. Does that mean Americans are "special"? Far from it, they're mere subjects of the application of natural governing principles. And soldiers or cops? Only in that their ability to be protected and to feel secure in their own country represents a government's legitimacy.
I don't necessarily disagree with anything in this comment, but I'd like to add that the very idea of lives having worth is to say they have some intrinsic value in and of themselves, not because the government places it upon them or because people respect that value.