Did the sinking of the Blücher in 1940 affect the outcome of the war?

In the conclusion to this forensically detailed book, the authors, one a naval historian, the other a retired naval officer who served in the Oscarsborg fortress outside Oslo – the cornerstone of the story – during the Cold War, ask: ‘What would have happened if Hitler had not unleashed his dogs of war on Norway in April 1940, or if Blücher had not been sunk?’ To which of course they reply that we shall never know.

They do, however, posit that in the worst case, Churchill might not have become prime minister, and the evacuation from Dunkirk would not have been the success it was. That’s not entirely new, but it’s not always remembered – Dunkirk especially – or at least not outside the authors’ Norway. The Christmas tree in Trafalgar Square isn’t merely a thank you.

Operation Weserübung, the German invasion of neutral Denmark and Norway, began in the early morning of 9 April.