I have very little regard for the capabilities of the Russian armed forces, and know from history that the Russians often bluff and will back down when directly confronted. Our passivity is what is making them more aggressive.
I suspect that NATO’s fear is that Russia can simply turn off the gas. It is still winter, too...
That said, and perhaps someone can answer this: Is not France (by virtue of its nuclear power plants and expanded oil / gas from Libya) somewhat less dependent on Russian gas? France did sign on to at least one, if not more, of the Security Assurances when the Ukraine gave up its nukes. Perhaps France could act unilaterally to assist the Ukraine? Putin would be on pretty thin ice if he tried shutting down gas to Europe because of what the French were doing.
The question then might be, outside of “prestige”, “what’s in it for France?”