Mossad is the common abbreviation for ha-Mossad le-Modiin ule-Tafkidim Meyuhadim or Institute for Intelligence and Special Operations, the main external intelligence and covert action organization of Israel. Its responsibilities correspond roughly to the U.S. Central Intelligence Agency and British Secret Intelligence Service. Mossad operates worldwide. As with those countries, it is complemented by a military intelligence service (Aman) ( and a domestic security service (Shin Bet).
According to its website, its missions are:
- "Covert intelligence gathering beyond Israel’s borders." This is principally human-source, but probably includes signals intelligence and measurement and signature intelligence collection outside the country.
- "Preventing the development and procurement of non-conventional weapons by hostile countries."
- "Preventing terrorist acts against Israeli targets abroad."
- "Developing and maintaining special diplomatic and other covert relations": liaison with foreign intelligence services, non-national groups, and plausibly deniable interactions with countries with which Israel has no diplomatic relations
- "Bringing Jews home from countries where official Aliyah agencies are not allowed to operate".
- "Producing strategic, political and operational intelligence.
- "Planning and carrying out special operations beyond Israel’s borders".
When clandestine operations become known, as in some of the cases below, through other governments, there presumably was a failure of security. Most intelligence services say their failures are trumpeted but their successes are known, and, with as highly regarded an agency as Mossad, there are probably far more undetected actions than are known in open sources.
Its director is Meir Dagan, whose appointment has been continued beyond the usual retirement.  He will have his term extended even further, probably into the summer of 2011, since the leaders of the Israeli Defense Forces (Gen. Gabi Ashkenazi) and Shin Bet (Yuval Diskin) also are expected to retire, during sensitive periods with the Iranian nuclear program and negotiations with Palestinians. Candidates to replace him are "Diskin; outgoing director of Military Intelligence Amos Yadlin; "T.", a former deputy head of the Mossad; and Hagai Hadas, a former senior Mossad official who is now Prime Minister Benjamin Netanyahu's point man for negotiations on the return of captive soldier Gilad Shalit." 
Britain, in March 2010, expelled an unnamed Israeli diplomat over the misuse of British passports, which were tied to the assassination of a Hamas official in Dubai. This may not have strictly been an espionage violation, but creation or acquisition of identity documents is a classic support requirement for both special operations and clandestine human-source intelligence. The support function may, due to operational security requirements, not know the ultimate user of the documents.
While the U.S. and Israel are presumably allies, there have been a substantial number of U.S. court cases dealing with Israeli intelligence collection, and it can reasonably be assumed that the actions are reciprocated.
Mossad has conducted assassinations, perhaps the best known directed at Black September, the perpetrators of the killing of Israeli athletes at the 1972 Olympic Games in Munich. The operations, personally authorized by Prime Minister Golda Meir, initially were conducted by two alternating teams, and struck their targets. As the teams fagigued, a third, less well-trained group relieved them, but, in a case of mistaken identity, killed the wrong man in Norway.
A senior Hamas official, Mahmoud al-Mabhouh, was assassinated in Dubai in 2010.  Security was inadequate and Dubai pursued Mossad members.
- About Us, Mossad
- Yossi Melman (7 May 2009), "Mossad officials jostle for top intelligence agency post", Haaretz
- Alef Benn (20 October 2010), "Mossad chief may stay on during 'sensitive period' of coming months", Haaretz
- "UK Expels Israeli Diplomat over Dubai Case", CBS News, 23 March 2010
- Israeli Espionage in the US, Council for the National Interest, 18 November 2009
- Hugh Tomlins (16 February 2010), "‘Mossad assassination squad used British passports’", Times Online (UK)