you do realise Royal Navy has 7 x Hunter Killer Nuclear Submarines Astute Class+ 4 x SSBN of the Vanguard Class each one carrying 16 Trident missiles and Trident has done over 180 test fires since induction
meanwhile both China and Russia combined cannot reach the kind of firepower
those old Soviet submarines are not reliable and Chinese ones are not sea worthy
which is why UK can send its assets to both China and Russia while neither can send their assets anywhere close to UK
or in simple terms, we can reach you but you cant reach us