That's complete and total nonsense.

That's not how war works and not how it has ever worked or will ever work. If a war is justified, then it is justified to not only repel the enemy troops from your borders, but to counterattack within their borders in order to reduce their ability to continue fighting. That does not make it "a different conflict" when you do.

I can't believe people are still dragging out the same absurd talking points that social democrats used a century ago when justifing throwing bodies into the meat grinder of WWI. "We are only fighting against defeat" they said. As if, in their minds, once the German lines were broken, the Allied forces were going to just stop at the border! It's completely and utterly delusional. Or rather, it is bad faith, because they knew, and you and I know, that's not how anything works.