A veteran U.S. State Department foreign service officer says his job is on the line after he posted a link on his blog to a WikiLeaks document.

Peter Van Buren, who has worked for the department for 23 years and just published a book that is critical of U.S. reconstruction projects in Iraq, said this week that the State Department had launched an investigation against him earlier this month for disclosing classified information.

His crime, he said, was a link he posted on August 25 in a blog post discussing the hypocrisy of recent U.S. actions against Libyan leader Muammar Qadaffi. The link...