The rationale for diplomatic de-escalation and not unilateral military action was Clarke's other point. In a nutshell, Iran has the ability already to make America pay for such a move. Iran, in Clarke's view, has thoroughly infiltrated southern Iraq with intelligence and military personnel. Should the U.S. or Israel drop one bomb on the Bushehr nuclear facility, says Clarke, these forces in Iraq have the capability to make the current insurgency look like child's play, implying that Iran can trigger the Iraqi civil war we've been fearing. Not only that, Iran has the capability to virtually shut down the flow of energy (oil and gas) from the Persian Gulf. Finally, Iran could quite quickly turn up the heat in Afghanistan, where it holds considerable influence with warlords Washington needs to maintain stability. Any of these moves would be an extremely effective check on American military action.
Clarke's conclusion was that use of military force was not an option with Iran. Clarke, however, resigned from his government post after 9/11 and blew the whistle on how this administration ignored intelligence about Al Queda planning a strike in the U.S. before 9/11.
This administration has a history of ignoring the interpretation of intelligence that Clarke advises.