“A strike on nuclear capability is effectively a ‘nuclear strike’ even if conventional weapons are used.”
No, it’s not. The STRIKE is not nuclear. Using conventional weapons to take out the launcher, or the transport vehicles, or command-and-control, is not a nuclear strike.
It’s like sinking a boomer with a depth charge or a conventional torpedo. Sinking that boomer would not be a nuclear strike. It would be the use of a conventional weapon to take out the delivery system.
Ditto for using a SAM to shoot down a bomber that is carrying nuclear-armed cruise missiles. The launch of that SAM is not a nuclear strike.
Sinking boomers and/or shooting down nuclear bombers in peacetime is the beginning of nuclear war, don’t fool yourself. A nuclear power will not sit and watch their nuclear arsenal be neutralized by ANY means.
You cannot assure a win by striking first. The entire system is designed to remove that option.