Iran surely cares about Mesopotamian dibs and the plans of the Western nations to counter her nuclear program. But in terms of her priorities and her modus operandi – undermining Israel, extending the reach of her brand of Islamism through covert action, and supporting terrorist insurgencies – a submarine in the Red Sea has direct, tactical application, and at a political juncture never seen before. No six-month period in history has combined the destabilizing political eruptions of the Arab Spring with the concerted effort of the Palestinian Authority and its supporters to press for a multilateral fait accompli against Israel. Those factors, in my view, are the ones at the top of the mullahs’ priorities list.
Iran will want to get the region accustomed to a “forward presence” posture from her submarines. The announcement was undoubtedly geared partly to that consideration. The submarine may show up shortly in a Red Sea port – perhaps Eritrea’s – in which case the prior announcement would showcase and defuse that event.
An Iranian Kilo is not a ballistic- or cruise-missile equipped submarine; it cannot be in the Red Sea to hold the territory of Israel or Saudi Arabia at risk. There is some strategic value, in terms of signal sending, to proving that Iran can bring this deployment off. But analyzing this development solely in that more abstract light is insufficient.
The final consideration is that Iran is probing the US with this move.