Some of the P(weapon failure) is constant: from what I hear, a certain fraction of Soviet and US systems (and presumably everyone else's) just don't work.
If that was all it was, then you would be correct.
But: some failures come with age, and require ongoing maintenance to retain function. For example, I expect all the tritium has decayed, and also that in many cases the money that was supposed to get spent replacing the tritium was instead spent on a fancy yacht or a football team or a seat in the UK's House of Lords etc.
And I don't know how good modern anti-missile weapons are, but I would expect them to have improved; conversely, despite Russia's talk about new hypersonic missiles, what they've shown hasn't been very impressive, and they've even used up some of their old nuclear-capable missiles while attacking Ukraine.
Some of the P(weapon failure) is constant: from what I hear, a certain fraction of Soviet and US systems (and presumably everyone else's) just don't work.
If that was all it was, then you would be correct.
But: some failures come with age, and require ongoing maintenance to retain function. For example, I expect all the tritium has decayed, and also that in many cases the money that was supposed to get spent replacing the tritium was instead spent on a fancy yacht or a football team or a seat in the UK's House of Lords etc.
And I don't know how good modern anti-missile weapons are, but I would expect them to have improved; conversely, despite Russia's talk about new hypersonic missiles, what they've shown hasn't been very impressive, and they've even used up some of their old nuclear-capable missiles while attacking Ukraine.