@Squiff70
Sorry to state the bleeding obvious but a deranged psychopath dictator has access to the nuclear button and has threatened to use it but that SHOULDN'T be taken seriously???

It's not so much that, as to whether he intends to or not makes a significant difference to relevant actions to take.
Put at the most basic level:
- Insane dictator means nuclear threats = we must not allow this man to overtake Ukraine
- Insane dictator doesn't mean his nuclear threats = we must not allow this man's threats to prevent us in supporting Ukraine
I've actually been subject to someone who had a very similar "I'll nuke you" mentality in business. Nothing was going to change the fact that he was unreasonable, bullying and determined to destroy us rather than negotiate. There were no sunshine and roses outcomes from the moment he began his campaign against our business. We could only steadily mitigate the impact on ourselves until his own unreasonableness undid him. It was painful, but entirely instigated by the man in question. You have to remember that these bullies are immune to reasonable outcomes, and only their own visualised outcomes are seen as valid. But that doesn't mean you cave and accept their vision of themselves.
(in essence, the man I was dealing with thought that he was entitled to take - TAKE - our entire customer base under his company - fundamentally ignoring the fact that a) they might not want to, b) there was no legal mechanism for doing so and c) he didn't have the operational capacity to do so - all the mistakes that Putin is making)