"Unless we act we are confronting an even more frightening future," Mr. Powell told a special meeting of the Security Council in a highly anticipated and strongly worded speech lasting slightly more than an hour. "Saddam Hussein and his regime will stop at nothing until something stops him."

Mr. Powell delivered the White House‘s brief against Saddam Hussein‘s regime in lucid, incriminating tones, describing a country that houses large stocks of chemical and biological weapons that have been tested on human beings, maintains a small network of elusive mobile weapons labs transported by truck and rail, and possesses an active nuclear weapons program — much of which Mr. Powell said Baghdad has concealed from United Nations weapons inspectors who have spent the last two and half months examining Iraqi arms programs.

Mr. Powell, who said that Iraq‘s sleight of hand violates the terms of Resolution 1441, the United Nations decree adopted last fall that requires Baghdad to cooperate with weapons inspectors, also said that Iraq has aided terrorist groups, including key cells linked to Osama bin Laden‘s Al Qaeda network. And he said that Baghdad has authorized its army to use weapons of mass destruction in battle.

"I cannot tell you everything that we know, but what I can share with you, when combined with what all of us have learned over the years, is deeply troubling," Mr. Powell said. "Iraq has now placed itself in danger of serious consequences."