Roughly a dozen years in both places unless you specialize, then add at least another two years to that. The only real difference between med school in the US and the UK is that in the US you'll be 200K in debt by the time you hang your shingle.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.