It probably prevents armed warships from attacking them. It doesn't, as you correctly point out, prevent guerilla warfare.

Thanks for pointing this out. I hear people say this over and over, if Iran only had nukes it would be safe to continue propagating terrorism as it has been doing. It’s obviously wrong, as you point out. Russia has nukes. India has nukes. Having nuclear weapons doesn’t mean you can do whatever you want, if anything it brings a higher level of scrutiny. A nuclear Iran would be a serious problem for many and that’s why it’s so critical to make sure that doesn’t happen, not just for Israel but the entire planet.

My totally unsubstantiated conspiracy theory is that several of those are sitting in shipping containers in the US and Europe, and that is part of the reason that their interests drive all western foreign policy, despite their open hostility to their 'allies'.