The effort here is exactly as you describe - once again attempting to take an innately immoral act - war - and phrase it as a moral obligation. This at once makes war seem good and stifles thought of other productive and more moral methods of a conflict resolution.

It's proven to be a wildly effective tactic because really, people are mostly good. They want to help other people, they want to see their fellow man do well. Harm to another human causes fear, pain, distress, anger, depression... even if we have no hand in the event whatsoever. Those who do often are afflicted with post-traumatic stress. Instinctively we know that is a bad thing, and an immoral thing.

So if you tell them that by supporting a bad thing, that means they're not only themselves good people, but will also be helping other good people? Even if it's a total lie, people will want to believe it because they want to feel good and they want ot help others, and like water, human thinking tends to follow the path of least resistance.

affect on the lives of civilians there, either long term or short term, I'd be for it. But we aren't talking about bombing missile silos that are about to launch a chemical attack, but a punitive measure, made weeks later, after the dead have already been counted. I hate to be blunt, but frankly, after this military strike, they will still be dead, and more people, just as innocent as them, will join them in the grave because of our actions.

which will have to be replaced. Money.