Oslo was signed in 1993. Had the Lubavitcher Rebbe, who was disabled in 1992, been around, he could definitely have rallied enough numbers in mass opposition and could have forced the Haredi parties to vote against it.
What would have been R.Kahane's tactic if he'd been alive in 1993?
Oslo is still on the table and further retreats are pending.
If Chaim was in Israel today, what would/could he do, bearing in mind that just for saying the words
"Aravim Hachutzah" will get you 18 months in Lod jail!