In a decision with potentially far-reaching implications, a U.S. court recently rejected the idea that international organizations enjoy absolute immunity from suit in the United States. The U.S. Court of Appeals for the Third Circuit, one of the appellate courts that sits between the federal trial courts and the Supreme Court, decided in OSS Nokalva, Inc. v. European Space Agency that international organization immunity is subject to the same exceptions as foreign states. That may sound obscure, but international organizations include institutions such as the World Bank, and some of the immunity exceptions could open up these institutions to significant new levels of accountability.
A bit of background here: In 1945, early in the development of the modern international system, the U.S. enacted the International Organizations Immunities Act (IOIA). The IOIA was passed, in part, to reassure the United Nations and other new global agencies that it was safe for them to have staff (and often headquarters) in the United States. The law states that such organizations will have the "same immunity" from suit as foreign states.
But what does that mean? The traditional practice was that foreign states, like diplomats, had absolute immunity from lawsuits. The only exception was if the U.S. government told the court not to recognize immunity; because the immunity of foreign states (also known as "foreign sovereign immunity") is designed to protect U.S. foreign policy, the U.S. government can decide that it's not necessary in a particular case.
By 1945, that practice was already changing, in two ways. First, the U.S. government was more frequently waiving foreign sovereign immunity; second, in cases where the U.S. government said nothing, the courts were developing general rules based on the government's past practice. Finally, in 1976, Congress decided to enact these rules in a new statute, the Foreign Sovereign Immunities Act (FSIA), which ended the case-by-case evaluation of immunity by the U.S. government. The FSIA creates a general rule of immunity as well as a series of well-defined exceptions that the courts can apply.