Most politicians justify their actions no matter how extreme. Look at Chenney for an example in recent times, or just go back a few decades and read what guys like Hitler had to say about their own actions.

Additonally you will find that current political leaders are no different in that regard. If you make a careful study of Obama's new found points of view since he has come to power you will find he now fully supports the idea of not only staying in Iraq and Afganistan as long as is nessesary to give himself "victory" but also invasion of Iran and North Korea as fully possible steps towards regiem change just for those very same reasons as admitted by Blair and others to justify their own endeavors.