The most shocking part of the accusations against Chalabi are not that he allegedly betrayed the United States by passing on our secrets to Iran, but that someone in the Administration trusted him with our secrets! Pelosi's broadside that the Administration has proven incompetent seems relatively mild in retrospect.
Here's a description from CNN.com of Chalabi's high access in the Bush Administration:
'A source of intelligence on alleged weapons of mass destruction when Washington geared up for war with Iraq, Chalabi was the beneficiary of millions of U.S. taxpayer dollars for his Iraqi National Congress, with easy access to top officials in Washington.
He was a "special guest" at President Bush's State of the Union address in January, sitting behind first lady Laura Bush. Bush had dinner with Chalabi and other Iraqi leaders during the president's surprise trip to visit the troops in Iraq last Thanksgiving.'