I don’t buy it one bit, not for a second. For all its pretenses about ideology, the Iranian regime has been incredibly pragmatic since the Iranian Revolution. I mean, they even bought US weapons from Israel during the Iran-Iraq war, helped the US topple the Taliban, and so much more. Iran has absolutely nothing to gain from assassinating the Saudi ambassador to the US and so much to lose. This whole scenario could well be part of a strategy to spin the recent and furious anti-Saudi regime protests in eastern Saudi Arabia, home both to Saudi Arabia’s oppressed Shi’i minority and most of the kingdom’s oil reserves, as part of a wider anti-Saudi conspiracy spearheaded by Iran, which, of course, is blamed for the protests. And, to be sure, the US is part of the spin. The US has a vested interest in discrediting the protests in Saudi Arabia. Much of US foreign policy in the Persian Gulf revolves around securing the dreaded and wholly authoritarian regime in Riyadh.
The Saudi dictatorship is the most important oil producing state. They not only have the largest reserves in the world, but more importantly, they have the highest capacity to produce the most barrels of oil per day. So if prices increase drastically, the Saudis, being the swing producer, can increase output by as much as 4 million barrels per day to bring prices down. In other words, the survival of this regime, however distasteful, is of utmost importance to the US and other foreign oil-dependent countries (the US consumers 20 million barrels per day!)
In that context, the protests in eastern Saudi Arabia are perceived by the US and Saudi authorities as entirely unacceptable and explosive, especially considering how protests have been mushrooming into revolutionary movements across the regime. Thus, the “conspiracy” alleging that Iran plotted to kill the Saudi ambassador could very well be part of the larger strategy to highlight Iran’s perceived anti-Saudi belligerence and to tie the demonstrations to this wider Iranian anti-Saudi conspiracy thereby discrediting the legitimate protests as part of a foreign plot.