The submarine: Not just a game changer, but nearly a crippler of the British Empire

British
military might rested on its navy for centuries, Paul Kennedy reminds us in The Rise and Fall of British Naval
Mastery, which I am just finishing. That changed
almost exactly 100 years ago with the advent of the submarine. "There is no
doubt that this new weapon almost brought the British Empire to its knees," he
writes.

By
1937, British spending on the RAF passed spending on its army, and a year
later, also passed the navy's budget.