Some people are speculating as to why the government of Iran suddenly decided to release the British sailors and Marines it was holding. There are a number of reasons that have been bandied about, and the two leading contenders are that we made some sort of terrible threat, or that we caved in and bribed them. Maybe both.
I think there’s another reason. The big game here is Iran’s program to produce weapon’s grade U-235, and what they need now is time. The big danger, as they see it, is that we’ll get nasty before they have a nuclear deterrent and start bombing.