Why are you referring to the Gulf War of 1990 when the topic (and the original article) are about the Iraq War of 2003?
Resolution 687 which did not end the war, but provided Saddam Hussein with a unilateral armistice under which he had an opportunity to renounce international terrorism and weapons of mass destruction (WMD) with their delivery systems. Everyone in the Security Council and Congress understood that a material breach of those requirements meant ending the ceasefire, and invading Iraq to resume the war authorized by Resolution 678.