Well, Iran has released the British hostages, which is excellent news for everyone, especially them and their families. Ahmadinejad said he was "pardoning them as a gift to the British people" in honor of Easter and Muhammed's birthday.
Britain needs to strike back as soon as its hostages are safe. The absolute minimum they can do is cut all relations of any kind with Iran, especially commercial relations, and freeze all Iranian assets in their power. Agreed, Britain probably couldn't launch a military action all by itself, and since nobody got killed, starting the shooting would look bad in the eyes of the Independent and those other surrender monkeys who blamed this whole thing on the Americans for capturing some Iranian agents inside Iraq.
Thucydides said that wars are fought out of interest, fear, or honor; interest and fear are already both factors in our dealings with the mullahs. And honor has just been lost. You can't let a tinhorn theocrat capture your sailors and then magnanimously pardon them, or no one will take you seriously again in that part of the world.
In strategy--and make no mistake, this is a game of strategy, I'm absolutely positive Iran planned this whole thing out--your opponent makes his decisions based at least partly on what he thinks you are going to do. Iran was betting that Britain and America would do nothing if it took some hostages, and Iran will have won its bet if there is no sharp and immediate response. If there is not one, Iran is going to up the stakes and see how far it can push in order to find out how strong the West's will really is. Be prepared for another stunt like this one in the near future, another test of strength.
By the way, I do not know what I would do if I were taken hostage by the Iranians. They wouldn't have to put too much pressure on me to get me to cooperate; I have no illusions about my own personal courage. I wouldn't smile for the cameras while shaking hands with my captor, though, and I wouldn't wish him success, either.