It depends. We've seen an *announcement* of drawdowns form the SPR (Strategic Petroleum Reserve) have an effect (post-Katrina) but it's a bit fuzzy. Iran threatening to close the Straits of Hormuz has an immediate effect on prices. The fact that they've never done it generally means the spike will eventually pass. The fact that Iran could pursue policies that end up with them being bombed back to the Stone Age would have even more unpredictability.