Gromit - “... We should spend more securing these shores, and not some far off ones.”
As an island nation, this means having a capable navy and air force with ships suitable for deployment in order to protect ourselves and our allies. This includes cruisers, frigates, subs, aircraft carriers (preferably with aircraft on them), destroyers, etc.
Scaling down out military capacity is potentially disastrous as is cutting back on our police force. This is short term politics at its very worst.
We were once a world power Gromit. And as a consequence of that and of living in enlightened times, it is seen as 'the decent thing to do' to protect those countries and communities that we once colonised if they cannot protect themselves. This is the legacy of our imperialistic past and we cannot and should not walk away from it. For example, the Falkland Islands were invaded back in 1982 and we went to war with Argentina. Were a similar invasion to happen tomorrow, I doubt that we would be able to do the same again.
But I don't suppose that matters because, after all, these particular British people do live a very long way away...