Complex sentence: Although most Israelis supported the Accords, the Israeli settler movement opposed them because Sadat would not agree to a treaty in which Israel had any presence in the Sinai Peninsula at all, Israel had to withdraw from the entire Sinai Peninsula.
Split into simpler sentences: Although most Israelis supported the Accords, the Israeli settler movement opposed them. Because Sadat would not agree to a treaty in which Israel had any presence in the Sinai Peninsula at all, Israel had to withdraw from the entire Sinai Peninsula.