https://www.bushcenter.org/about-the-center/newsroom/press-releases/2021/09/remarks-president-bush-shanksville-9-11.html

As a nation, our adjustments have been profound. Many Americans struggled to understand why an enemy would hate us with such zeal. The security measures incorporated into our lives are both sources of comfort and reminders of our vulnerability. And we have seen growing evidence that the dangers to our country can come not only across borders, but from violence that gathers within. There is little cultural overlap between violent extremists abroad and violent extremists at home. But in their disdain for pluralism, in their disregard for human life, in their determination to defile national symbols, they are children of the same foul spirit. And it is our continuing duty to confront them.

*Twenty years. ago, we had terrorist attack from abroad. Now we have terrorists from within.