US Kills al-Qaeda Commander

Last week, a UAV killed a top al-Qaeda commander in Pakistan. He is apparently responsible for much of the violence in Afghanistan. The fact that he was killed in Pakistan is very interesting, because the president of Pakistan has repeatedly said that he will not allow the US to strike within his country. I think this poses an interesting question. To what degree can a country violate the sovereignty of another government in the name of fighting terrorism. I think it's interesting to imagine what it would be like if someone did that to America. Like if Spain killed a Basque leader somewhere in America. Obviously, the government would be upset. Of course, I whole-heartedly approve of killing terrorists. But shouldn't we also be careful to not step on the toes of friendly governments? I'm wondering what everyone else thinks about this. Do you think it's okay to disregard a government's sovereignty in the name of the global war on terror?