He fled Iraq after the fall of the monarchy in 1958. Chalabi earned a Phd degree in Mathematics from Chicago University. In 1977 he established the Petra Bank in Jordan.
A Jordanian court sentenced him in absentia for 22 years to prison with hard labour. He fled Jordan in 1992. In that same year he established the Iraqi National Congress (INC) in London. The INC was funded by the CIA and received over $100 million in the first half of the 1990s to topple Saddam Hussein. In 1995 Chalabi tried to initiate a rebellion in northern Iraq.
On 31 August 1996 the Iraqi army stormed INC bases in Northern Iraq killing hundreds of INC militia members and forcing others to flee including Ahmad Chalabi. He returned to Iraq after the occupation in 2003.