Original: Stephen John Hadley (born February 13, 1947, in Toledo, Ohio) was the 21st U.S. Assistant to the President for National Security Affairs (commonly referred as National Security Advisor), serving under President George W. Bush.
Simplified: Stephen John Hadley (born February 13, 1947, in Toledo, Ohio) is the current (21st) U.S. Assistant to the President for National Security Affairs (commonly referred as National Security Advisor) for President George W. Bush.