Ahmad Chalabi, the Iraqi politician who from exile helped persuade the United States to invade Iraq in 2003, and then unsuccessfully tried to attain power as his country was nearly torn apart by sectarian violence, died on Tuesday at his home in Baghdad. He was 71.

The cause was heart failure, Iraqi officials said.

Mr. Chalabi (pronounced CHAHL-a-bee) was the Iraqi perhaps most associated with President George W. Bush’s decision to invade Iraq and topple its longtime dictator, Saddam Hussein.

A mathematician with a Ph.D. from the University of Chicago, Mr. Chalabi, the son of a prominent Shiite family, cultivated close ties with journalists in Washington and London; American lawmakers; the neoconservative advisers who helped shape Mr. Bush’s foreign policy; and a wide network of Iraqi exiles, many of whom were paid for intelligence about Mr. Hussein’s government.

Mr. Chalabi’s relationship with the Americans stretched over decades. In 1998, he helped persuade Congress to pass the Iraq Liberation Act, which was signed by President Bill Clinton and declared it the policy of the United States to replace Mr. Hussein’s government with a democratic one.