Justin Logan, a Foreign Policy Analyst at the Cato Institute, writes a cogent analysis on the current options for dealing with Iran:
It appears increasingly likely that the Bush administration’s diplomatic approach to Iran will fail to prevent Iran from going nuclear… evidence strongly suggests that the disadvantages of using military action would outweigh those of acceptance and deterrence… Iran is deterrable and would be particularly so if faced with the devastating repercussions that would result from the use of a nuclear weapon. Therefore, the United States should begin taking steps immediately to prepare for a policy of deterrence…
In summary, Bush is not going to war against Iran anytime soon.