If, technologically, it is possible to make an impenetrable device or system where the encryption is so strong that there's no key - there's no door at all - then how do we apprehend the child pornographer? How do we solve or disrupt a terrorist plot?

I don't wanna preempt an announcement next week. And there's a lot of technical aspects to it. And if I - say - that we're doing one thing. then the markets might interpret it differently from what it ends up being.

And terrorists who seek to harm our citizens will feel the long arm of American justice.

I face the world as it is and cannot stand idle in the face of threats to the American people. For make no mistake, evil does exist in the world.

Perfect is unattainable. Better is possible.

Let's remember that our leadership is defined not just by our defence against threats, but by the enormous opportunities to do good and promote understanding.

So I have known Islam on three continents before coming to the region where it was first revealed