The most fully articulated case for war in Iraq was presented in Secretary of State Colin Powell's February 5, 2003, speech to the United Nations Security Council. After establishing the context for the speech, this essay examines the strength of that case, focusing especially on structure, reasoning, and evidence. The structure was appropriate to the purpose, if somewhat unusual. Although the speech relied on argument from ignorance, this inference was reasonable in context. The fatal flaw in the speech was the unreliability of key evidence. More critical questioning of evidence at the time could have brought this problem to light and perhaps have avoided some of the consequences that followed.