We don't really have the ability to enforce the law with respect to illegal work in this country in a way that's truly effective...We haven't been able to require every employer to enter a system in which they check the work status of their employees and determine whether they're legal, and without that, we don't really have the ability to enforce the law with respect to illegal work in this country in a way that's truly effective. And that would be the single greatest additional weapon we could use if we're serious about tackling this problem.

I'm sometimes asked why it is that for 30 years we seem to have trouble in the United States enforcing the rules against illegal immigration, and I'll tell you what the answer is. The answer is that when the television cameras turn off and the spotlight moves to something else, there are a host of interest groups and advocacy groups who work very, very hard to make it difficult to enforce these rules. I'm not commenting adversely on their motivation, but I can tell you the effect of all of this is to wear down the ability of an agency to enforce the law.

So people have to decide. Do they want to have the security? Do they want to continue to plug the gap [in border security] that GAO has identified and recognize that there will be some costs to doing that? Or do we want to make sure that business isn't hampered and that people can move back and forth readily, and recognize that, if we don't put some barriers in place, we're going to wind up with dangerous people coming into the country?

The Department of Defense took 40 years to get where it got.

But one thing that we have done in the last four years is we have really put pressure on the leadership of this organization [Al Qaeda]. We have killed a significant number of leaders. We've captured others. Those that remain have to look over their shoulders, they have to be on the run. So that even if we don't manage to kill or capture them all within four years, what we do do is put the kind of pressure on them that makes them focus on their own skins, as opposed to carrying out attacks.

Al Qaeda is very media-savvy and very focused on what goes on in the global media.

I have not heard a report of thousands of people in the convention center who don't have food and water.