Inspectors do not have the duty or the ability to uncover terrible weapons hidden in a vast country. The responsibility of inspectors is simply to confirm evidence of voluntary and total disarmament. Saddam Hussein has the responsibility to provide that evidence, as directed, and in full
Whatever new threats and challenges may emerge, our nation will be able to face them squarely, deal with them, and yet allow our people to continue to live free and unafraid. The decisions you make, the courage and creativity you bring to your responsibilities, will determine America's future. Liberty and our way of life are fragile gifts - their care is in your hands. We thank you for stepping forward to shoulder that immense responsibility. Your country is grateful, and proud of each of you.
There's another way to phrase that and that is that the absence of evidence is not the evidence of absence. It is basically saying the same thing in a different way. Simply because you do not have evidence that something does exist does not mean that you have evidence that it doesn't exist.