ok am gonna assume you are sincere in wanting to know the difference. 

1.    Imperative: In this context, an imperative means something is necessary or unavoidable due to circumstances (e.g., self-defense, protection of innocent lives). This doesn't necessarily imply moral approval or justification for war.

2.    Justification: Justifying war implies that the act of waging war is morally acceptable, which can be problematic. War often leads to significant human suffering, and it's essential to question whether the ends (whatever they might be) justify the means.

If I am forced to kill then I will. That is different than saying it was right. 

 So protecting innocent life is not morally justified?  

 you are playing word games now i think but I will try one last time in case you really dont get it. 

avoid war if you want to protect the max number of human lives fren. Life is the ultimate aim. Life and thriving. We need to cheer that. 

 What if a war would kill 100k but would save 1m in the long run? What if it kills 1 innocent for every 10 innocents it saves? I just don't get why you have to simply something that is notoriously complicated.  

 *simplify 

 it is not complicated.

You described an imperative. That does not mean we should glory in or assign moral rectitude to the ritualized (rules of war) mass slaughter of human beings.

This is not some deep philosophy. Life is good. Death is bad. Avoid war. Dont call for it if you are not ready to die in it. this is very simple. 

 

 When did I glorify it? You are projecting.  

 I tried. Be well. 

 People can't do the kind of math you're talking about because we don't know the future. You can't say this will save 900K lives. The world would be a better place if governments weren't in the business of industrialised, ritualised killing of poor people to make the rich richer, aka war.  

 I was just illustrating a point. Every action you take is anticipating the future, even if there are big uncertainties involved.  

 You should read Machiavelli. It's instructive. Here is an exerpt that deals with this from the pragmatic prince perspective but makes it clear that it is wrong.

And it must be understood that a ruler, and especially a new ruler, cannot always act in ways that are considered good because, in order to maintain his power, he is often forced to act treacherously, ruthlessly or inhumanely, and disregard the precepts of religion. Hence, he must be prepared to vary his conduct as the winds of fortune and changing circumstances constrain him and, as I said before, not deviate from right conduct if possible, but be capable of entering upon the path of wrongdoing when this becomes necessary. (Machiavelli, 1988: 62) 

 Think of it like this: While an imperative acknowledges the necessity of a particular action, justification implies moral acceptance or approval. There's no moral justification for mass ritualized murder; however, recognizing an imperative doesn't necessarily mean you condone or justify war.

It changes how you address, approach and regard it. Cheerleading is frivolous froth or dangerous goading when the war gods come. The first time you hear a mortar incoming will change your perspective or make you a demon. we unfortunately may find out soon if the cheerleading continues.

war should be faced and contemplated by those who are prepared to die. It makes wars more scarce and aggression more difficult to fund.