For we have always understood that when times change, so must we, that fidelity to our founding principles requires new responses to new challenges, that preserving our individual freedoms ultimately requires collective action.
I remember, right after Hezbollah launched its rocket attacks on Israel, I said: This is a clarifying moment; this is a chance for the world to see the threats of the 21st century, the challenge we face.
Whenever I look at the history of presidents I deeply admire - the one thing that I'm always struck by is persistence. It's a quality that's underrated. Being able to plough through, being able to stay buoyant in the face of challenges.
I'm not able to go in with an act that I use month to month year to year all the time. It's constantly evolving and changing and that keeps me on my toes but certainly adds to the challenge.