Greatest Threat

Here is a quote Colby found from Colin Powell, former cabinet member:

What is the greatest threat facing us now? People will say it's terrorism. But are there any terrorists in the world who can change the American way of life or our political system? No. Can they knock down a building? Yes. Can they kill somebody? Yes. But can they change us? No. Only we can change ourselves. So what is the great threat we are facing?