Oh my god they are all so fucking pathetic

That depends on the deterrence and escalation models adopted by state actors. Most escalation and deterrence models state that states escalate because they believe they can gain an advantage by moving the conflict to a higher level of escalation. So with the framework you're proposing, nuclear states with a weak or effectively non existent conventional force, may adopt a first strike nuclear policy, and threaten to escalate to nuclear strikes at very low levels of conflict/escalation in order to prevent war breaking out, or a defeat on the conventional battlefield. North Korea is an example of a state that uses this framework, and many want Iran to follow a similar framework. On the complete opposite end of the spectrum, a state may deter an adversary from escalating a conflict by ensuring it has a relative advantage in forces at whatever level the conflict is currently in – for example, the United States with its gigantic military. As the United States has a much more capable military at almost all levels of conflict over almost all adversaries, it should be able to deter escalation from almost anyone at any time, in theory.

The problem with the first model is that it's vulnerable to "salami slicing/chipping away" at red lines, and requires the state to launch nuclear first strikes at the smallest of provocations, with all the downsides of such a policy. Also, adversaries with a much larger nuclear arsenal will always be able to respond with much more weapons in a nuclear conflict. This is why alliances like NATO and the Warsaw Pact formed in the first place. Conventional armies are important for deterrence at lower levels of escalation. North Korea is in a very unique situation, their direct adversary in South Korea does not have nuclear weapons, and relies on the conventional force deterrence of the United States to deter conflict. It's also why I think that Iran will not become a nuclear atmed state unless they think the threat from Israel is existential and unavoidable.

Relying on just nuclear weapons to prevent conflict, and to deter and compel (two very different things) on their own with any conventional force to back them up, I think is unrealistic for Europe. The idea that, once you have nuclear weapons, you can use them to essentially freeze time with regards to the relationships between two adversaries. And the idea that, once two opposing sides have nukes, regardless of how many either has, conflict or any form of escalation outside of it would become frozen as both sides would be deterred from taking any action. I'd consider these ideas unrealistic and a reckless faith in the nuclear arms revolution in the context of a Europe without NATO.