Israel has at least 3 submaries capable of carrying nuclear weapons
There are the old Dolphins and the new Dolphins, they are very different. It is the new Dolphins which are supposed to have the second-strike nuclear capability and Israel just got the first one in the series. See e.g. here.
Israel has protocols for direct nuclear answers
I am sure it has. But the situation when you tracked a long-range bomber from Iranian airspace and that bomber dropped a nuke is very different from the situation when a nuke just exploded in a city and you have no idea how that happened or who is responsible.
Especially if Iran announces that should we be hit in retaliation, we will use all of our (remaining) nuclear weapons.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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