My guess is that the tanker attacks were carried out by elements of the Iranian Revolutionary Guard. Whether they were specifically sanctioned by the government or not is unclear. On the one hand, Rouhani has less control over the Guard than one might think; on the other, the Iranians are past masters at the use of plausible deniability.
In the end, it probably doesn’t matter; Iranians close to the government will be found at fault, and the regime will have to pay the price. But how, exactly?
I predicted years ago that Trump would go to war with Iran, and that a naval issue like this would be the most likely precipitant. I am sticking to my story, although war over this particular incident is not completely inevitable. The real question is whether the Trump administration will cut the grass, go in some way for regime change, or annihilate the country altogether, given that an Iraq-style invasion and occupation is not in the cards.
I think we will start with a fairly robust aerial assault on the Revolutionary Guard, accompanied by a stern warning that any retaliation will result in the use of nukes. Since nuclear threats are now a familiar part of Trump’s diplomatic tool kit, and nothing has happened, the Iranians will probably blow it off. How does Trump respond when they call his bluff? That’s when things get really, really dangerous.