The water in the Persian Gulf is quite the challenge for ASW in acoustics.
That doesn't make it impossible, just hard.
Can anyone confirm that the Iranian Kilos ARE IN FACT including the AIP option?
I don't recall (it's been a few years) that mod being on the original offering, based on what was available to me, but it has been so long that perhaps something is going on in that regard.
Also, for a local/defensive situation like Iran is in, the Kilo need not be AIP to be very effectvive and difficult to deal with. See the difficulties with San Luis off the Falklands to see why that might be.
The problem Iran has is getting the buggers to sea. Once at sea, for a given period, they can manage a wide variety of mischief if operated by a capable captain and crew.
Hmm, any Iranian captains ever take the Perisher course?