The whole scenario is quite ludicrous though. We spend an extremely high amount on having a credible sub based nuclear deterrent. This to ensure we never have to use our conventional forces in a major conflict, or face attack by conventional
munitions. (most likely from Russia). So you could argue the need to scope conventional forces for a major conflict?
I do see where you're coming from and it seems bizarre to say that we have a nuclear deterrent to deter Russian (and others) aggression but at the same time that we need strong conventional forces to also deter Russian aggression. But that is the reality you do need both (when dealing with a nuclear armed state anyway).
Take, for instance, a slightly different version of reality where NATO's conventional forces were even weaker than they already are (perhaps little more than glorified border guards) and Putin hasn't wasted the best equipment and personnel on a futile war in Ukraine. Russia invades the Baltic States, they are NATO members and request Article 5 assistance. But NATO has nothing in the locker other than nuclear weapons. The first response is also the last resort. Putin is willing to gamble that we're unwilling to start a nuclear war over the subjugation of the Baltic States so invades anyway and then what do you do? The war continues and Russia launches cruise missile strikes on military targets in the UK, no civilian casualties but significant damage and loss of life amongst the armed forces, your conventional forces are unable to effectively strike back nor prevent further attacks. Do you use nuclear weapons now? Etc etc.
Unless you have a the conventional forces to resist a conventional Russian attack you're trapped into either nuclear war or submission.
Now, we don't live in that world. Even European NATO sans the US retains a significant latent military capability, more so with the addition of Finland and soon Sweden and the Russians expending themselves on Ukraine, but it is very fragile. There isn't much depth in terms of available equipment nor crucially in terms of ammunition and there we're only ever so slowly getting anywhere near addressing the industrial decline that has left us unable to ramp up production of munitions even as basic as 155mm artillery shells. Let alone the more sophisticated systems like Storm Shadow which is proving quite effective at the moment (see Sevastopol). We'd run out of ammunition in a week and then be up the creek without a paddle. Even if we didn't run out of ammunition we'd simply run out of vehicles, artillery pieces, aircraft and ships not long after that anyway and then same creek, same lack of paddle.
We have a nuclear deterrent but the cold reality is that you cannot just get by with nuclear weapons and no or extremely limited conventional forces. You need to have sufficient conventional forces such that any possible opponent knows for a fact that if they attack you, you will be able and willing to resist and indeed you might even win a conventional fight.
Of course you may also need conventional forces to deal with nations that don't have nuclear weapons of their own. We had nuclear weapons in 1982 and could certainly have threatened Argentina with nuclear annihilation. I'm pretty sure if we'd glassed Buenos Aires in mid-April they'd have surrendered the islands in short order afterwards. But we'd also have been international pariahs on a level with the likes of North Korea and guilty of a monstrous crime that I'm not sure could ever be forgiven. That sort of conflict requires conventional forces and, if you wish to avoid fighting those sorts of wars the best thing you can do is maintain a strong conventional military.
Yes...Russia's actions in Ukraine will have focused the minds of our politicians, but whether we will actually see any real increase in military capability is open to debate.
Signs point to no so far, plenty of words but that's about it. I've lost all faith that any of our politicians actually consider national defence anything other than a nice to have to be ignored the first time it actually requires difficult decisions or spending.
I'd say conventionally...there is still no real military threat to the West at present.
Agree to disagree! Russia is too wounded from its imperial adventures in Ukraine to pose a significant threat for a while even if the war ended tomorrow but it would be foolish in the extreme to presume that the peace and security we've enjoyed since 1989 will continue indefinitely. Russia will, absent a seismic internal shift, always remain a latent threat and will no doubt attempt to beggar its population to rebuild some fraction of what its lost. China is out there in the midst of the greatest military build up since the 1930s and 40s. Other parts of the world are destabilising around us. Trump could well win a second term in 2024 and he does there's every chance he could try to pull the US out of NATO and without the US we lose a gargantuan chunk of NATOs military potential.
To continue to act as if it 1995 is deeply unwise. I'm not trying to be alarmist nor suggest that we (and others) should immediately double or triple our defence budgets and build forces the size of which we haven't had since the 1980s. But it's time to arrest the decline, deepen the magazines, rebuild the defence industrial base, put more ships, aircraft and armoured vehicles into service.
The point of having an effective military is to make an attack by a potential enemy unappealing. If your potential enemy thinks that they don’t have a very good chance against your military, they are unlikely to try invading.
As the old saying goes: "If you want peace, prepare for war". It might seem counter intuitive, but there's more than a grain of truth to it.