I think we're talking past eachother.
I'm saying: Whether or not the Russians consider their silos to be more or less survivable than their truck-based missiles is immaterial, and doesn't change the calculus at the strategic level, because one of two things has to happen in a first-strike situation:
- You blanket the entire country in nuclear detonations and pray that you catch all the trucks scurrying around like nuclear-armed mice
or
- You spam dozens of missiles at a small number of hardened targets and hope you dent them (missile sponge silos)
Either way, you're severely depleting your arsenal to an infeasible level to do this. These are both counter-force attacks where targeting is the only difference, which the Strategic function does not concern itself with. That's a tactical consideration. Survivability of a land-based asset achieved by different means is still survivability of a land-based asset. In other words, it's still functionally a triad.
In the case of France in particular, the argument I recall reading is that: a) France was entering a period of austerity in defense spending as the Cold War ended, b) its siloed missiles were obsolete and in need of upgrades which promised to be costly, and c) France isn't very large geographically, so the "missile sponges" were limited to that little plateau north of Marseille which is pretty darn close to several major population centers, where an Ivy Mike-sized airburst could endanger Avignon and Marseille, not to mention leave a plume of fallout all the way into Germany.
But I'm just an ex Air Force officer who's been to France a bunch, so idk how accurate that is.
>The real reason for silos is, if you want to build a truly insane number of strategic warheads, silos are the only way to afford it
On this I'm in complete agreement.