Now Sir Keir has faced a similar issue, with successive previous government, including the Conservatives, severely cutting the Defence Budget and placing the UK in a "unready for war" state. He now must somehow "make time" with the diminished military and he has already started the process to rebuild, after the previous Conservative Government did make a good decision; to build two full aircraft carriers. They just need a full back up of supporting destroyers , and cruisers, let alone many more F35's. The trouble is, in the 21st century, developing and rebuilding the military takes significant time, which the issue of HMS Dragon highlights, in its own way, with time needed to build up stocks of munitions, and having no real back up to this specialist vessel. The very issue that many European countries are now facing. The Ukraine War has also dramatically shown, to all militaries, that the nature of warfare has changed and has led to a major review of how to conduct a modern fight for survival.
Aircraft carriers are from the 1970s. These days, they are just sitting ducks—as are most other surface ships. As for the F35s, they are inordinately expensive and are arguably inferior to other 5th gen aircraft available elsewhere.
Yes, modern warfare is has changed dramatically and is now dominated by such things as drones, hypersonic missiles (for which neither we, nor the US, currently have the technology), EMP weaponry and all sorts of advanced EW systems.
The days of battleships, lumbering tanks and ground armies will be consigned to history books—there is no place for them in future military confrontations.
Building up a sizeable defence force for the next century would be prohibitively expensive. With ex-service personnel currently living on the streets, it would be as obscenity to throw billions on committing to a larger military "for our survival". We are not under threat.
Far better to establish non-aggression treaties with as many countries as possible—but that involves diplomacy. The future for all of us on the planet depends on rational, honest and possibly even friendly, behaviour...not thinking that we know best how other countries ought to be ruled. What is that approach doing for the US?
And, these days, the UK is hardly a good example of a well-functioning democracy!