American vs British thriller

Why are there no thriller spy novels or crime novels where the Main Investigator is American and ends up in London or vice versa? Cross Atlantic intrigue? Or have I not found them.
Are British thrillers and American plots so different? Americans love a good government conspiracy — this goes back to our roots of how and why we had to leave the Homeland, the Mother Country in the first place (English Civil War, I’m thinking of you mate!).
Not sure if this is so with Britain. Britain has Sherlock Holmes in its cultural background, but James Bond was a post-War invention by Ian Fleming who supposedly did some espionage work with some sort of secret agency. Are British fears / thriller points more about those who want to invade UK from without? As a small island nation, that might be primo in its goings on.

Not that I want to see Sherlock Holmes meet Dashiell Hammet or anything. YET London-Los Angeles stories would be so so interesting because they are polar opposites in so many ways. And yet so similar too.