The report that a group of Iranian “students” has entered the British Embassy and begun to vandalize the facility is more than disturbing. In the early reports there is no word about the safety or whereabouts of embassy personnel. Nor do we yet have any idea what the Iranian government will do in response to the occupation.If the embassy personnel are safe and undisturbed and if the government moves to clear the protesters from the embassy grounds quickly, the incident will pass relatively quickly. There may be some lingering disputes about compensation and liability, but the problem will be contained within the normal diplomatic process.If on the other hand, the “students” are permitted to remain in the embassy, or, worse, if there are problems with the safety, security and free movement of UK embassy personnel, we could face a crisis worse than the crisis over the 1979 attack on the US embassy. At that time the Iranian Revolution was still young and both the rulers in Tehran and the authorities in Washington had reason to seek compromise.This time, the embassy attack comes as the chances for conflict are rising. The Iranian government needs to step very carefully at this point; attacks on embassies are acts of war and crises once started can take on a direction and build a momentum of their own.