10 Must Brutal Acts Of Revenge In History

2. Mossad Agents Sent Letters To The Families Of The Palestinian Terrorists Who Killed 11 Israeli Athletes... Just Before Murdering Them

The Munich Massacre saw 11 Israeli Olympic team members taken hostage by the Palestinian splinter group Black September and murdered along with a German police officer during the 1972 Games.

Although five of the eight Black September members were killed by West German police and the other three were arrested, the survivors were eventually released following a Lufthansa airliner hijacking in October of the same year.

In response to this, Israeli intelligence agency Mossad - literally meaning "the Institute" - launched "Operation Spring of Youth" and "Operation Wrath of God" in order to track down and murder all Palestinians suspected of involvement in the Munich Olympics Massacre.

Operation Spring of Youth saw a Mossad raid on Palestine Liberation Organisation (PLO) targets in Lebanon in April 1973. Three high-ranking PLO officials were murdered, as were many other members of the group, as well as two civilians and two Israeli soldiers.

Meanwhile, Operation Wrath of God - or "Operation Bayonet" - targeted both the PLO and Black September for the 20 years after the Munich Massacre and was orchestrated by Israeli Prime Minister Golda Meir in the autumn of 1972.

Hunting down these Palestinian splinter forces over the next two decades, tens were killed - and before they were murdered their families would receive flowers and a condolence card reading: "We don't forgive and we don't forget."