The Israeli secret service has a history of clandestine operations and first gained notoriety in the 1960s when its agents kidnapped Adolf Eichmann in Argentina, the SS officer and key architect behind Hitler's "final solution".
Eichmann was approached on the street, grabbed by the throat and, within seconds, bundled into a getaway car. Passers-by were unaware anything had happened, though Mossad said that the abduction took 20 seconds, 10 seconds longer than planned.
After trial in Jerusalem, he was found guilty of war crimes, crimes against humanity and crimes against the Jewish people and was hanged on May 31, 1962.
The Institute for Intelligence and Special Operations ('Mossad' in Hebrew means 'The Institute') was founded in 1951 and is one of the world's smallest intelligence services, with a staff of just 1,200.
Its strength, however, lies in its back-up system of tens of thousands of 'sayanim' ('helpers' in Hebrew) within the global Jewish community. This network provides safe houses, finance, cars and medical assistance -- whatever is required by agents.
The Israeli equivalent of the CIA, it differs from most secret services in that while it rarely acknowledges its role, it likes its assassinations to be high profile enough to act as a warning.
It is accountable only to the prime minister who, according to Gordon Thomas, author of Gideon's Spies: The Secret History of the Mossad, personally provides Mossad with each licence-to-kill for specific targets.
Its network of spies is so accomplished that it has infiltrated the highest ranks of Arab governments. The most famous example was when Mossad agent Eli Cohen, who had befriended Syrian President Amin al-Hafez, came close to being named Syria's defence minister in the 1960s.
The Mossad has been feared for its determination ever since Prime Minister Golda Meir ordered the agency to hunt down and kill the Palestinian terrorists who massacred 11 Israeli athletes at the Munich Olympics in 1972.
Every one of them was targeted in an operation known as 'Wrath of God' -- the killings took place in Rome, Cyprus, Paris, Beirut, Athens and Rome. The last, Ali Hassan Salameh, was killed by a car bomb in Beirut in 1979.
On March 20, 1990 a three-man Mossad team arrived at Bull's apartment block in Brussels. As the 61-year-old answered the doorbell, he was shot.
Scientists working on projects for Israel's enemies are only too aware of the list of colleagues who have been assassinated. As recently as last month, Iranian nuclear scientist Massoud Ali-Mohammadi was killed by a bomb detonated in Tehran.
Hamas top man Mahmoud al-Mabhouh joins a long list of terrorists eliminated by Mossad.
Fathi Shaqaqi, a founding member of the Islamic Jihad terrorist group and responsible for multiple atrocities within Israel, was assassinated by Mossad in October 24, 1995.
He was due to leave Malta and go to Libya, where the Mossad believed he was to discuss details of a terrorist attack with Colonel Gadaffi. As Shaqaqi strolled along the waterfront later that evening, he was shot six times in the head.
Mossad's ability to eliminate targets where others have failed has made them the envy of the spying community. Imad Mughniyeh, responsible for the bombing of the US Marine base in Beirut airport, killing 241 people, had a $20m bounty put on his head by the US government.
In 2008, the Mossad reportedly rigged a car bomb into his rented Mitsubishi Pajero and detonated it by mobile phone. The blast blew his head off -- but the $20m was never collected.