On Dec. 14, 1981, Israel annexed the Golan Heights, seized from Syria in 1967. (Go to article.)
It seems that they fudged a bit on the history. The phrase "seized from Syria" makes Israel look like the aggressor. From 1948 until the Six Days War ended, Syria constantly attacked the Israeli agricultural settlements in the land below the Golan. The Golan Heights were used by the Syrians for aggression against Israel. Menachem Begin was confident that if Israel annexed the Golan, like it had done to eastern Jerusalem, there would be no way that any, even the most left wing government, would be able to give it to the Arabs.
When Begin gave the Sinai to Sadat, he kept insisting that the new communities built in Gush Katif would be permanent, in exchange for those he destroyed. He also kept saying that he was giving away the Sinai, so that we could keep Judea and Samaria. He was very naive. It was Begin's precedent of destroying Yamit, Ofira etc which facilitated and "legitimized" Disengagement and the present nightmare of threats and pressure.