Barack Obama: “I am proud of the new START Treaty and our joint efforts to reduce our nuclear arsenals.”

I think when we act on that basis, it doesn't always work out, but over time things do get better.

It is a decision about how do we face and embrace this finite amount of time we have on the planet.

A drift towards extremism was "not inevitable

When we choose, when we make that decision, I do believe – and there is evidence for this – that the world gets incrementally better, and that is a worthy goal and it’s worth fighting for.