The Iranians have seen close up what happens to a country when the US or 'the West' invades. I think you could count on much stronger resistance than was offered by the Iraqis. Iranians are extremely proud of their cultural heritage and will not willingly see it ransacked.
In the view of the Daily Telegraph, these sailors were taken because Tony Blair expressed regret about the slave trade, which apparently makes Britain appear weak in the eyes of the rest of the world.
Oh, and please steer clear in the discussion of anything that looks like advocating nuclear annihilation, even if not meant seriously.
Resistance isn't an issue if we don't intend to stay. How can this conversation not be about nuclear annihilation, that's sort of the point?