Heh, I do think that this is part of a trend to Iranian strategy: short term gains for long term losses. That is to say my initial impression of the particulars is that the confession was forced, the claims are dodgy and the Britishers are not prisoners but hostages.
From that I could say that what Iran as a whole tends to do is make plays that force the hand of their opponents immediately. This comes at the cost of credibility- it'd be kinda hard to take them seriously if you know they only make dishonest plays. What I'd like to know (or be reminded of, anyway) is to what extent Iran is a 'team-player' within the Middle-East, and how pervasive this anti-West/anti-US sentiment is.
What further complicates the matter was the reaction to/reality behind the recent announcement that there was a "possible diplomatic solution"- the Iranian way isn't a united way. You need to know who holds sway over what before trying to get the country to do this or that, and I think that's a pretty big tangle to unsort.
