It would be nice to consider a short period "rebuilding time" for planets that have been ravaged by war, universally agreed upon. It makes sense that, in a galaxy ravaged by constant war, that even sides that disagree on fundamental levels would come to the agreement that their aggression does have consequences on assets that they claim or seek to claim.
I mean, if you just destroy everything, then what's left to take? Logic dictates that Sith, Jedi, Mandos, et al, are going to be out of luck if they run out of things to conquer, or reasons for which to do so. If you strip a planet of its valuable resources, it becomes less valuable. If you kill all the inhabitants, there's no impetus to trade. If you glass it just to rebuild, you pay the opportunity cost of losing everything that was already there.
As much as I disagree with government intervention on a fundamental level (Alkor, you evil Libertarian scumbag!), I think that taking the time to recuperate after tensions come to a head is important. It's something that nations do now, in fact. Or endeavor to do. Sometimes you just can't get people to agree. (Looking at the middle east, here.) A strong example of this would be the surrender of Japan after Hiroshima/Nagasaki. Sure, they were forced to this point by... uh... nukes... but they had to rebuild their country. And their enemy even helped, after the fact.
(If you can call forced occupation, seizure of resources, and profiteering help, at least.)