Whether or not innocent people are killed it is the government's duty to protect its own first and foremost. I believe to ensure security those who would pose a threat should be eliminated before they can carry it out.
As long as civilians are not harmed in the operation, I can't see anything wrong with it. These people have people have no respect for human life, and have no remorse in ending it. These kind of people would blow themselves up anyway, so what wrong his us helping them along, without the innocent deaths.
The problem with this sort of action is that it could also result in the deaths of innocent people. Depending on where the action takes place, the police may be able to isolate terrorists, thereby ensuring the safety of the rest of the population. This, however, is not usually the case, and people uninvolved in the terrorism end up getting hurt or killed during the process of subduing/killing the terrorist.
Improving society by planned police actions to kill terrorists is just plain stupid, and would involve living in a police state. Killing terrorists by planning out there killing is just as bad as the terrorists, themselves. Apprehension and a legal trial would be the humane thing to do. Go ahead and catch them, but just planning to kill them makes us terrorists, as well.
I feel that any kind of planned attacks promote more violence. If it becomes necessary to use self defense to protect one's self, then that is acceptable. I do, however, feel that a plan of action should be set and in place in cases of imminent danger or activity. I do not agree with a movement that is initiated by the United States in an attempt to "go and find" terrorists. All measures and use of intelligence should be sought out first in an attempt to detain and punish terrorist, setting an example for others. The violence has to end somewhere and continuing it is futile.
Murder is murder, whether it is officially sanctioned or not. Yes, terrorists are evil, but we do not have to be evil with them. Catching them and putting them on trial for their crimes is a more just solution and it makes us the better person, which can be difficult but it is important to keep our morals.