Both. Danzo engineered the slaughter of a clan for their eyes so he could have power. If he wanted peace and what was better for Konoha he would not have murdered Shisui and stolen his eye. Danzo did not care about Konoha. Maybe at one time he did but he came to hold becoming hokage and having power as more important than what was best for the village. His behind the scenes actions caused the Akatsuki and his sanctioning of Orochimaru allowed Oro to be able to get Sasuke.
Sasuke has been gone from the village along time. He is not aware of the changes that have taken place. The Kages might have been a bickering, one upping bunch of leaders, looking for a way to have their own village come out on top at the Kage Summit, but Sasuke's and Obito's actions that day helped to change that. The Kages are working together now. They have come to respect each others actions. Look at the friendship that has arisen between Gaara and Onoki. Onoki has really come through in this war and has been able to admit that they have made mistakes that have led to the current situation. Ay has come a long way too and has realized that other villages also have good people that are worth listening to and protecting.
Sasuke would rather kill them instead of seeing if the war has changed them. He would rather kill them than find out if they have changed enough to know that things cannot continue as they are. Onoki who is the oldest of them already realized this, who is to say the others have not. Mei has already made changes in her village. Gaara is trying to change his. They should be given a chance instead of just executed.
Sasuke is no different than Danzo who would rather slaughter a clan instead of finding another solution. Hiruzen wanted to try other things and Danzo went to Itachi and threatened him with Sasuke instead of waiting for Hiruzen to come up with another way. At this point I don't see much difference between them. The two when both of them choose murder to solve the problem. Sasuke knows that BZ, Madara and Obito were working behind the scenes and controlling many of the things that shaped the hokages actions. Madara and Obito were completely controlling one of the Kages and yes that would affect all of the other kages and villages actions.
I am not saying that Sasuke is as evil as Danzo but he is selfish, egotistical like Madara, and also like Madara he thinks he knows what's best for everyone else. Just like it took two opposing forces to seal Kaguya it will take the two ways of handling things coming together and compromising to change things. Forcing his will on everyone else will turn out for him like it did for Madara, Obito and Kaguya.
