Complex sentence: Operation Last Chance was launched in July 2002 by Simon Wiesenthal Center in order to track down ex-Nazis still in hiding, as most of them would be nearing the end of their lifetimes, hence the operation's name.
Split into simpler sentences: Operation Last Chance was launched July 2002 by the Simon Wiesenthal Center with its mission statement being to track down ex-Nazis still in hiding. As most of them would be nearing the end of their lifetimes, hence the operation's name.