Please explain the phrase "the war becomes perpetual when it is used as a rationale for peace"?

It`s incorrect. No single war is perpetual, but war as a concept could be perpetual. War in generalized terms could be perpetual. What are the reasons for war? To acquire something that someone else has....land, resources,riches, to punish someone because of their political, religious, or idealogical views, to subjugate them and make them slaves, to annihilate them, to defend yourself from an aggressor,or to acheive peace. If you felt you HAD to go to war, which of those reasons would be good enough? To defend yourself, and acheive peace, so it`s not a rationale, it`s a goal. That is, if you are an honorable people. If not...you could use it as rationale for taking what is not yours, or punishing those you don`t like.

To Rationalize something, in essence, is to come up with a reason as to why something that is possibly absurd, or ridiculous, is supposedly not. So, in this case, the phrase is inferring that, the war in question is needed, or required, in order to sustain peace. And, in turn, for peace to be perpetual, so must the war.

War = Peace (To put it simply, is what the statement infers)

War should never be a solution for peace because it ( war) in itself is violent and therefore hypocritical. Peace should come about by words not guns.

To resolve differences that disturb the peace we wage war to bring peace and so on and on.

"Fighting for peace is like f***** for virginity!"