How do you interpret this:

I will never hesitate to use force when it is required. Any attack will be met with a swift and certain response.

Here is the scenerio:

A new enemy (not Al Qaeda) got hold of a nuclear device and plans to detonate it in the US. From what was said above, do you believe the US would attack the enemy after they nuke us as seems to be implied above or would the US prempt an attack.

If you believe the US would prempt please explain how the quote in italics clearly states that.