Dick Cheney, a pivotal figure in U.S. politics and one of the most powerful vice presidents in American history, has passed away at the age of 84. His family confirmed his death on Tuesday, attributing it to complications from pneumonia and cardiac and vascular disease. Cheney, who served as vice president under George W. Bush from 2001 to 2009, was a driving force behind the 2003 U.S. invasion of Iraq, a decision that remains highly controversial.