Why did britain, a former enemy, propose a common policy on latin america?

Britain proposed a common policy on Larin America because the Monroe Doctrine satisfied the demands of the British, which kept the French, Dutch and Spanish out of America, as well as sustained  trade with them. Furthermore, it allowed the establishing of the "Informal Empire" greatly of South America, where Britain constructed the telephone networks, dominated trade and railways. As a matter of fact, America was  in no position to regulate and control the doctrine, but the US Navy was too small, on the other hand, the Royal Navy is the largest navy in the World until 1946, could control  it.