Vienna : For an organisation about to celebrate its 50th anniversary Sunday, there is little sign of partying at the headquarters of the International Atomic Energy Agency (IAEA).
The agency, with its current Director General Mohamed ElBaradei at the helm, emerged into the public limelight as the UN's nuclear watchdog in connection with secret nuclear programmes uncovered in Iraq, Libya, North Korea and Iran.
Efforts by the IAEA to resolve those crises, however, met with less than universal acclaim.
Critics are quick to point out that the IAEA, an autonomous body within the UN system, often found it difficult to maintain the balance between promoting peaceful uses of nuclear energy and attempting to prevent nuclear proliferation.
Today's organisation, with 144 member states and an annual budget of 284 million euros ($390 million), was founded in 1957, propelled by fears of nuclear energy, then a new and controversial technology.
Under the motto "Atoms for Peace," around 2,200 employees promote projects ranging from food safety to cancer research or sterilization of tsetse flies.
When the IAEA statute entered into force on July 29, 1957, no one thought that one day agency inspectors would have to deal with rogue states or a nuclear black market for potential terrorists.
After the end of the Cold War, the IAEA expanded its safety role in the East, monitoring storage of nuclear material from dismantled weapons or recovering orphan radiation sources posing a danger to people and environment.
Aspects related to nuclear terrorism gained greater focus after the Sep 11 terrorist attacks on the US.
As guardian of the Nuclear Non-Proliferation Treaty (NPT), in force since 1970, the IAEA's role shifted ever more towards becoming a nuclear watchdog.
The IAEA safeguard system is designed to verify a country's adherence to the NPT, a treaty intended to prevent the spread of nuclear weapons and weapons technology.
The effectiveness of the verification regime was first called into doubt after the discovery of Iraq's clandestine nuclear weapons programme in 1991.
Iraq brought about significant changes in the IAEA inspection regime, among them the introduction of the so-called Additional Protocol, granting broader inspection rights to the IAEA.
The new system was put to the test when North Korea became another country to violate its NPT obligations.
IAEA inspectors where thrown out of the country in late 2003, only to return this July, after North Korea agreed to mothball its weapons programme in exchange for financial and economic aid.
In the months before the 2003 Iraq war, the IAEA came under pressure from Washington to produce evidence for an Iraqi weapons programme.
ElBaradei's refusal to present a "smoking gun" led to long-lasting friction with the Bush administration.
Since 2002, the IAEA has been investigating Iran's nuclear programme, which the country has kept hidden for 18 years.
Iran's refusal to cooperate fully with IAEA inspectors prevented the agency from clarifying the scope and intent of Tehran's nuclear ambitions.
In 2005, champagne flowed in Vienna after the IAEA and ElBaradei were awarded the Nobel Peace Prize. But winning the prize was not uncontroversial.
Widely regarded as a snub to the Bush administration, the hypocrisy engendered in the IAEA's double role was blasted by anti-nuclear activists.
The IAEA was accused of playing down the risks of nuclear power and indirectly promoting military uses.
While Iran and North Korea continue to make front-page news, the – according to its director general – chronically under funded agency, will have to adapt further to fulfil its role for the next 50 years.