Where has Iran miscalculated?
According to this, not only is the US critical of the breaking of the seals, but also China and Russia.
Iran is making the same kind of mistake that Iraq did: it thinks that a couple of sweet-heart deals and back-alley agreements have bought both a Russian and a Chinese veto in the UN security council.
Iraq thought it had done that with the French (under Schroeder, the Germans abdicated their foreign policy to the French) having been successfully bribed (Food for Oil connections there go into the highest levels of government) that the UN would never vote for going to war: they were formalistcally right, but didn't realize that you don't have to have approval of the UN to go to war. It's a diplomatic nicety, but it's not a necessity.
Now Iran is apparently convinced that either the Russians or the Chinese will stay bought and prevent any sort of UN sanctions, vetoing any sort of final warning.
Major miscalculation, just like Iraq.
Because of their intense desire to be taken seriously, pushing their agenda and their timing way up, well before they are really ready. They know that time really isn't on their side once their goals become clear: rather than slowing down their preparations and moving more secretly one slow step at a time - the North Korean way - they push and push and push out of political necessity: their own demographic problems point to a time in the not-so-far future when the grandchildren of the revolution enter their political majority and cannot be pushed around like the current generation.
So they make public mistakes and draw attention to their plans, just as the Iraqis did.
But in their perception of the world, where the Muslim is humiliated and downtrodden - regardless of whether this is true or not - and everyone is aligned against them - for increasignly legitimate reasons - and where the mere existence of the non-Muslim is an affront to their core beliefs - and don't believe for a second that this isn't one of the key issues here - and where the world is a zero-sum game, the leaders of Iran can't take the waiting and press on towards catastrophe.
The question is: what will the Butcher's Bill be now? The destruction of Tel Aviv-Yafo and the following destruction of Qom, Teheran, Mashad, Esfahan, Tabriz, Shiraz? Three mn Israelis and Palestinians and 16 mn Iranians?