This is going to be a bit of an opinion piece. I'm sure I can find articles to support my thoughts, but this is one of the things I really learned in my ISP (International Security Policy) concentration at SIPA.
As Dr. Betts would say every year as he met the ISP incoming class: War is a serious business. It's about life and death. If you're not a serious person, get out and don't join ISP. At the time I thought he was just trying to scare off people who might waste his time. Now, I tend to agree with him.
I'm a pacifist, first and foremost. I generally think that violence is the tool of the desperate and unimaginative. Violence is easy to commit, easy to do, easy to justify. Nonviolent solutions to conflicts are difficult, hard to manage, confusing and require a pretty strong belief in the capacity of mankind.
US (and many other countries') leaders seem to approach war in a piecemeal fashion. Let's send 10,000 troops...which will take a year from order to boots-on-the-ground...and haggle over how many copters, what kinds of guns, etc. Bombing campaigns are popular and expensive. Like sanctions, they 'send a message' and don't cost a lot at home in terms of political support.
Fighting a proper war requires sacrifice, commitment, political will, lots of money, lots of imagination, lots of planning (and a clear set of goals!!), a well-trained military, civilian counterparts who understand something about war and clear communication. If you are haggling about troop numbers, I feel like you don't truly realize that you have to commit totally (i.e. fighting a total war to win even a limited war). If you aren't willing to commit, don't go in the first place, because the costs and realities of war will drag you to give more and more than you expected and then you'll be stuck fighting a total war anyway.
So, I'm in a funny place as a pacifist. Don't go to war, don't use violence. Ironically, my study of war reinforced my pacifism, since its clear that the costs of war escalate unless you have a lot of factors and will in your favor. So, don't go unless you're going 100% and are willing to pay the price in deaths, casualties, money, popularity and moral confusion.
(note, this is not an argument for increased violence in war, just better preparation. Fight smarter, not more brutally (brutally is counter-productive and just legitimizes and galvanizes your enemies)
I'll write more later that relates to others' analysis. I look forward to counter-arguments! :)