It would undoubtedly be an interesting dynamic when the intelligence community didn’t trust the PM - as I think would happen. Without opening up a detailed discussion, the question of national security, our place in the world and the UK’s ongoing association with the Five Eyes partnership would to my mind be at risk under a Corbyn administration. And given that all our recent operations have been conducted in an international / alliance context, that is a big issue.
Not that I would expect Corbyn or his acolytes to worry about that. They would probably be quite happy to sideline the entire intelligence and security architecture, citing an anti-democratic agenda.
And beyond our military partnerships and alliances how does all that translate? A lack of ‘Understanding’ (see JDP 4
https://assets.publishing.service.go...ing_jdp_04.pdf), some pretty questionable statecraft and a general mess in terms of our entire approach.