How do you feel about the UK maintaining an arsenal?
@danny23?
It's not merely a deterrent from other nuclear strikes - which is obvious mutual destruction anyway - it's a deterrent for any kind of hypothetical direct military action being taken on the UK by any states which, in either the present or future, possess greater conventional war capabilities simply for the potential consequences it presents.
You get what you pay for and it's as minimal as it is credible. If you're only going to pick one form of deterrent between sea-based SLBMs, land-launched ICBMs and/or tactical aircraft bomber capabilities, the SLBMs are definitely the way to go and nuclear-powered submarines are both the most reliable and least vulnerable to being taken out. The British Vanguard-class SSBNs are equivalent in quality to US kit.
Of course, the bilateral US-UK Mutual Defence Agreement for direct collaboration on the design, development, maintenance and exchange of materials for thermonuclear weapons is among the most significant and exclusive treaties in existence and firmly underscores the political, and economic ties between the two. It's actually written into US law and decennial renewal (due next in 2024) is not debated nor voted on in UK parliament.
It's also likely in contravention to the international Non-Proliferation Treaty, but who the fuck is going to do anything about it?