Board Thread:Naruto Discussions/@comment-26388300-20150603054656/@comment-734582-20150606111807

Rachin123 wrote: In retrospect it makes a whole lot more sense. Danzo was expecting to fight Madara afterwards. His only move on Madara was sishui's eye, which needed to recharge, and which was why he needed time. Killing sasuke would mean Madara (the real madara) would've blitzed him in two seconds. I mean, Danzo's pretty strong but has nothing, absolutely nothing on Madara.
 * Danzō vs. Sasuke: There were a few times that Danzō could've killed Sasuke but that couldn't happen because he's important to the story so basically the battle was crap.

If he had realized it was "only" obito, as Tsunade pointed out, the war would probably not have happened and Danzo probably would've risked fighting him right after Sasuke. Because Obito is strong, but Madara was orders of magnitude above him. Five kage had nothing on Madara. One kage was enough for Tobi.