Yesterday the arrest of two men for intending to blow up the Saudi ambassador to the United States was announced. The plot, going through Mexican druglords, sounds improbable. But countries and people do dumb things, so that's not a reason to reject it.
Not much information has been released so far. It's not at all clear, for example, how involved the Iranian government might have been, the possibilities ranging all the way from a rogue drug operation to direction by the Supreme Leader or President Ahmadinejad.
It could also be entrapment by US drug or other agents, a plot cooked up by another group (national or not) to embarrass somebody, or totally made up by the guy who got caught. We won't know until we have answers to these questions, at least.
So it's extremely premature to claim that this has anything at all to do with Iran's nuclear weapons, since we don't know how involved the Iranian government was involved in any of this. But that hasn't stopped at least three commentators (here, here, here) from going there. (I know, the reference to Iran's developing an EMP capability should disqualify it too.)
A question that I haven't seen anywhere is why this came up now. There have been some slightly placatory noises coming out of Iran about its nuclear program, and before other negotiations there have been accusations of Iran on various grounds. Iran also has an election coming up.
It could be that it was just a matter of how things happened. But the FBI and other agencies have made arrests before at times that seemed like they could have been intended to influence negotiations, as with Gennadi Zakharov before Reagan and Gorbachev met in Reykjavik in 1986.
Again, is it a coincidence of timing or an attempt to look strong before a negotiation? And, if the latter, how far up does that intention go?
Update: A caution from Reza Marashi and Trita Parsi.