Sanctions imposed by the Bush administration on Iran are sure to worsen already strained relations between Washington and Tehran. The measures target the 125,000-strong Iranian Revolutionary Guards as well as more than 20 commercial companies.
The punitive measures are the harshest imposed on Iran since its 1979 revolution and the subsequent US embassy hostage crisis. Nor do the measures affect just Iran.
The sanctions and their consequences will be felt globally. Any business continuing to trade with Iran risks harsh reprisals by the US. The sanctions make it illegal for any US citizen to knowingly provide material support or resources.
This is largely academic as the US has had few links or contact with Iran since 1979. But the impact will still be felt, if not in the US then internationally, especially by non-American companies that have business interests in both the US and Iran.
The US decision to act reflects frustration at the refusal of Russia and China to support tough economic sanctions against Tehran in the UN. The Security Council is deeply split on Iran and Washington has made its displeasure known to friend and foe alike.
The move also reflects the decline of American diplomatic focus. Instead of encouraging a broad consensus it is acting on its own, making it clear that the lessons from the build-up to the Iraq invasion have not been taken on board.
In one sense, the two countries share more common interests than at any time since the hostage crisis. The situation in Iraq and Afghanistan is of concern to both.
Yet relations between the two countries are marked more by accusatory statements than diplomatic niceties. The one major issue separating them is Iran's nuclear drive but that makes it more imperative, not less, for the two countries to speak to each other.
