WASHINGTON - A retired US Marine Corps general who last served as vice chairman of the Joint Chiefs of Staff pleaded guilty on Monday in a federal court to making false statements to the FBI during an investigation into leaks of classified information. Four-star General James Cartwright was questioned by the Federal Bureau of Investigation in 2012 over a book written by New York Times reporter David Sanger, which exposed a malicious computer software program known as 'Stuxnet' designed to disrupt Iran's nuclear program.