US Sailor here. Iran is actually pretty scary. They have diesel submarines. They can sit silently in that sea and kill a carrier faster than any battle group could respond.
The short answer is “it’s complicated but yes, and practically no.” Nuclear submarines have the operation range to obfuscate their location orders of magnitude better than diesel. Diesel is quieter but their range makes tracking infinitely more feasible. “A needle in a haystack vs a splinter in pail of hay.” Nuclear is better at power projection, diesel is better at short range defense/offense.
Look at it this way: When a diesel sub is endangered, they can turn off everything and I mean EVERYTHING. Quiet as a mouse that doesn't exist. However, it will have to resurface eventually.
A nuclear sub cannot do that. The cooling pumps have to keep running. But they can stay under water pretty much indefinitely (until they run out of food).
Nuclear subs have cooling systems that need to be working constantly. This creates additional vibrations/noise on top of the propulsion system.s that would be pretty similar between both subs. As well as nuclear subs needing to be much bigger, so require propulsion that produce more noise
Diesel submarines can literally turn off every system and just drift in the ocean currents silently, or loiter on the sea floor where they are indistinguishable from a rock.
Worth noting nuclear submarines have a sort of minimum-practical-size determined by the need for a functional nuclear reactor on board. Combined with the plain expense of nuclear reactors means that states can build way more ssk's than ssn's for a given budget.
It's often better to have three 25% chances of sinking the other guy than one 50% chance.
It's often better to have three 25% chances of sinking the other guy than one 50% chance.
Three 25% of sinking is the same as three 75% chance of not sinking. Which is (3/4) * (3/4) * (3/4) chance of not sinking, which is approximately a 42% chance of not sinking, which is a 58% chance of sinking. 58% > 50%, the math checks out.