US Attorney General Eric Holder (R), Preet Bharara, US Attorney for the Southern District of New York (C) and FBI director Robert Mueller (L) announce a plot was foiled involving men allegedly linked to the Iranian government to kill the Saudi ambassador to the US. Photo credit: Getty Images

By David Gardner, international affairs editor

The US accusations that Iran is behind a plot to assassinate the Saudi ambassador to the US – possibly by blowing up a Washington restaurant he frequents – are, frankly, weird.

There is presumably some substance to it; it is the US attorney general and head of the FBI announcing the charges, and the Obama administration is clearly taking the plot very seriously.

But there are obvious objections. Why would Iran so up the ante in its three decades-long cold war with the US, by carrying out an outrage on American soil? While what we are accustomed to thinking of as the Tehran theocracy is no monolith, and a rogue operation is possible, what urgent motive could there be to strike the US and the Saudis now? Read more