Democracies don't go to war against each other, and by and large they don't sponsor terrorism. They're more likely to respect the environment and human rights and social justice. It's no accident that most of the terrorists come from non-democratic countries.

We should cooperate with others in the fight against terrorism around the world, in whatever ways are appropriate and possible. Because it's a global threat, invulnerability is global.

If, as it now appears, this was an act of terrorism it was a despicable and cowardly act. We will find out who was responsible and hold them accountable. If their intention was to deter us from our mission of promoting peace and security in the Middle East, they will fail utterly.

I think it's both good ethics and good economics to scrap this notion that we can fight a war on terror and give rich folks like me a tax cut. It amounts to class warfare.

During the Vietnam War, any young men -- including the current president, the vice president and me -- could have gone to Vietnam but didn't. John Kerry came from a privileged background and could have avoided it, too. Instead he said, 'Send me.'

The war against terrorism is one we must win.