Did they? The Annenberg Political Fact Check reviews White House administration statements quoted in an anti-war newspaper ad and finds that even if the factual basis of their precise words is debateable, their intent to deceive is not. They lied.
They started with what they needed people to believe in order to win support for a cynical and greed-fueled military agenda, and then grossly and perversely stretched a few threads of not-yet-disproven "intelligence" around their conceptual framework.
And now the United States is in true peril for the first time since the Cold War.