“This is probably a silly question-but why doesn’t the UK grow and raise more of their own food? History says they provided for themselves in the past.”
When you live on a cold rock in the middle of the North Sea, you need to import food and you need to colonize other parts of the world.
As for the Brits, the problem is going to be the wine.
France, Italy, Spain and Argentina may play hard ball.
Britain used to be self-sufficient in terms of food, even not having to rely on Irish farms. Ever heard of the Agricultural Revolution there?