The publication of the U.S. National Intelligence Estimate on Iran on December, 2007 profoundly affects the Iranian nuclear crisis. It has given a false sense of confidence about Iran’s program: it is likely that the reported interruption of some dedicated military activities in 2003 was a tactical, short-term decision rather than a strategic, long-term one. Other components of Iran’s program continue, including uranium enrichment, which could give Tehran a “nuclear breakout” option. Because it undercuts the rationale for military action and further sanctions, the NIE will make the settlement of the Iranian nuclear problem evenmore complex and difficult than it was before.