August 22 was a deadline set for Iran to respond the U.N. Security Council. On the day of the deadline, Iran provided a proposal to European diplomats which the Iranians claimed cited “positive and clear signals.” The Bush Administration said it is still studying the Iranian proposal but that the reply of the Iranians “falls short of the conditions set by the Security Council…..which require the full and verifiable suspension of all enrichment-related and reprocessing activities.”
Here is a great explanation of why “the obvious next diplomatic step is to show Iran that the world meant what it said by following through with the toughest achievable sanctions.”