Before answering this question, I want to explicitly set out what I think it is actually asking. The question asks about arguments that would justify “an extended range of options to meet national security objectives.” I take this to mean that you are being asked to justify (or to reject) the use of tactics, for the purpose of achieving national security, that are unconventional and might be seen as unethical. In other words, it is asking whether we can justify things like drone attacks and “enhanced interrogation techniques” on the grounds that they are needed to protect our national security against the threat of terrorism.
In this answer, I will look at these two options that might fall into the “extended range” mentioned in the question. I will look at the use of drone attacks and I will look at the use of torture against terrorists. In both of these cases, I think that the actions are morally justifiable, at least in some situations.
With drone attacks, there are at least two issues. First, can we kill people who are not in uniform, who are not actively trying to kill or hurt us at the time of their death, and who have not been convicted of crimes in a court of law? Second, can we ethically and morally take actions that might kill innocent people along with the guilty? As to the first issue, I would argue that we can. We clearly have the right to defend our own country from those who would attack us. Since the terrorists have chosen to attack us when not wearing uniforms, we can assume that they would consent to be treated as combatants even when they are not in uniform. The fact that they are not actively engaged in trying to attack Americans when they are hit by drones is irrelevant. We would not hesitate to kill uniformed soldiers in a war who were not attacking us at that moment. Finally, when there is no practical way to capture and try our enemies in court, we are not obligated to attempt it.
Turning to the issue of torture, I find myself much less certain. On the one hand, I believe that we have the right to do almost anything to a guilty person in order to protect ourselves from further attacks. For example, if a person attacks me and I wrestle him to the ground, I have the right to hurt him if he continues to struggle. If I capture a terrorist who might know about imminent attacks on my people, do I not have the same right to harm him to prevent him from harming me? On the other hand, this argument could also be used to justify the torture of regular soldiers in conventional wars, which is something I do not approve of at all. This makes it hard for me to set a moral or ethical rule for when torture is acceptable. The best that I can do is to say that terrorists choose to engage in illegal actions, thus putting themselves outside the law. When they knowingly choose to reject international law, they waive their right to be protected by that law.
One caveat I have here is that I can only justify torture if it actually works. If torture does not actually make us safer, then there is no justification for employing it. I understand that there are many who argue that torture does not cause people to tell the truth. If that is the case, then torture is pointless and unethical.