Complex sentence: United Nations General Assembly Resolution 4686 revokes UN General Assembly Resolution 3379, which had equated Zionism with a form of racism, after Israel makes revocation of resolution 3379 a condition of its participation in the Madrid Peace Conference of 1991.
Split into simpler sentences: United Nations General Assembly Resolution 4686 revokes UN General Assembly Resolution 3379, which had equated Zionism with a form of racism. Israel had made revocation of resolution 3379 a condition for Israel's participation in the Madrid Peace Conference of 1991.