Complex sentence: In 2007, Senator Barack Obama's chief foreign policy advisor, Navy reservist Mark Lippert, was called into active duty and recruited McDonough to serve as his replacement during Lippert's deployment to Iraq.
Split into simpler sentences: In 2007, Senator Barack Obama's chief foreign policy advisor Mark Lippert, a Navy reservist, was called into active duty. Lippert recruited McDonough to serve as his replacement during Lippert's deployment to Iraq.