"We just got here!" is the most notable quote here. In every age there will come a mad man, who will easily fool the young into thinking of war as a glorious and exciting thing. Few will notice that older people, people who have been to wars, will have very different take on the matter. The old know but can't speak, the young don't know and can't think. That's why we always forget the struggles that won the peace we enjoy, and go back to repeating the mistakes of the past.
Pay close attention to what Joseph Heller says about war, most especially towards the end. What comes to mind immediately is; "What would he have had to say, just a few years later with 911 and the Iraq war behind us?" That question sort of proves his point in a way that no mere words could ever do. If one might hope that the Bush adm., might be held to account, that's not going to happen for reasons of national sovereignty and, while we could do it internally, that can't happen either because there are just too many interlocking issues and too much culpability spread around. Such that finding a reasonable border line, would be all but impossible, that is, unless one wishes to engage in some hundred year long debate. Thus the answer becomes that, since we don't know how to do this thing, it's best left to the scholars, bloggers and dust collecting library shelves.
On the bright side, we do have a more modern government that prevented the kind of excesses that were available to pre-Bonapartian ruleers. Where, unlike most legacy government paradigms, the powers of state are more widely distributed. Even that homeless person, sleeping under a bridge, enjoys the protection of some government power, at least in theory, and can assert some statutory rights, enforced by the powers of state.
If one steps back and looks at the problem from "the side of the board" it looks much different than it does to the players inside. Which explains why many very good and sundry suggestions on government, never make it into the codes of law, we simply do not know how to make them practically workable. How, for instance, does one circumscribe executive immunity, without effectively removing it, to such an extent that the executive is hamstrung? While we can speak of "stepping over the line", in reality those "lines" are not lines at all, but very wide, blurry, grey areas. While the "kibitzers view" is borne of hindsight, which we know is 100%, don't be persuaded by it, instead try to turn it around and garner or fashion some guide of conduct that can be used for future events. That is where hindsight and the "kibitzers view" fails.