Anyone who thinks they can control escalation through the use of nuclear weapons is literally playing with fire.

Escalation is escalation, and nuclear use would be the ultimate escalation.

We were not entering an arms race because we bilaterally have a verifiable inspection regime for the weapons that are deployed.

Is there a way that we can do this in a more cost-effective manner?

I think we should maintain our policy of not using them first and using them as a credible deterrent.

I hope that as we go forward and try to figure out what the new nuclear deterrent needs to look like we don't imagine that we have to have absolutely everything.

Credible deterrent is not just about how many nuclear weapons you have, but it is also about maintaining an open dialogue.

We absolutely have to have a nuclear deterrent because, unfortunately, there other countries--and hostile countries like Russia, North Korea--that have nuclear weapons.

I don't think we should simply say, 'Well, it is important so we are going to spend whatever it takes.'

I appreciate the focus on our nuclear weapons deterrent for this week. I think it is incredibly important.

We have to have enough of a deterrent to make sure that they never use them because they know that it would lead to their own destruction because of the size of our deterrent.