S3 (Missile)
en.wikipedia.org
en.wikipedia.org
In the article^0 where I discovered this (a, so far, interesting history of French and Chinese programs), I also found this part^1 interesting:
TN 75 Warhead
In 1984-1985 Defense Minister Paul Quiles tasked the CEA to design a miniaturized nuclear warhead for the MSBS M45 SLBM, a variant of the M4. In response, the CEA declared that it could 'achieve a warhead/ re-entry vehicle which is virtually invisible to radar' by 1994.15 The CEA launched the TN 75 warhead program, which was tested numerous times up until July 1991, when testing ceased. According to a report by the Defense Committee of the French National Assembly, 22 tests were conducted to develop the TN 75.
The TN 75 warhead is a miniaturized, hardened, thermonuclear warhead. A new coating material and a 'very precisely computed shape' are said to provide the TN 75 re-entry vehicle with 'a very high penetration' capability that also reduces the warhead signature. I? The warhead is much lighter than the current TN 71 (deployed on the M4B) 18 The TN 75 is in the natural progression towards warhead miniaturization, hardening, safety, and stealth, but the tight weight and volume constraints of this system forced design compromises that, when viewed from the prospect of a CTB, caused French officials to be concerned about the long-term reliability of the warhead. It is likely that the 1 October test conducted at Fangataufa, with a reported yield of 110 Kt, was probably a full-scale test of the TN 75.
0: https://news.ycombinator.com/item?id=36010490
1: French and Chinese Nuclear Weapons Testing, p. 46
France has always valued this Force de frappe; the idea was to convince the USSR that "France is not a prize worthy of ten Russian cities".
They don’t have enough weapons to target military infrastructure any French nuclear strike is going to be leveling cities, hence their focus on small number of high yield fusion weapons.
According to wikipedia the French have 280 deployed nuclear weapons. That's a lot.
I believe the explanation for the high yield bombs is exactly the opposite of what you are proposing.
A strike aimed at just killing as many civilians as possible is best done with lower yield weapons. Russia has 2 very large cities (Moscow and Sankt Petersburg); for any of the other cities using high yield weapons has very diminishing returns. I just modeled on nukemap [1] a strike against Russia's third largest city, Novosibirsk. A 100 kT bomb kills about 156k people while a 1 MT bomb kills 486k people. An ten fold increase in yield results in a three fold increase in casualties. If you go to Belgorod, a ten fold yield increase results in less than double the number of casualties.
Where high yield nuclear weapons make sense is against military hardened targets. There a 100 kT bomb might not damage a missile silo, while a 1 MT bomb might obliterate it.
That target btw was (at least as far as there late Cold War goes) the complete obliteration of 50 of the largest cities in the USSR, the destruction of 40% of its industrial capacity and the immediate death of 20% of its population.
And back then they target the USSR not Russia so Poland and East Germany as well as other soviet republics were on their target list and very publicly so.
France hasn’t really reduced their nuclear stockpile since the Cold War, their doctrine also hasn’t change much in fact they are the only country which said that it is willing to respond to terrorism with nuclear weapons if it comes to that.
So yes their doctrine is very much still deterrence through unimaginable punishment.