Question

How is isolation the most effective policy

Answer 1

From my point of view it is not so effective since it is like living in a neighborhood and not talking to the neighbors. You can live like that but it would be hard. Countries need other countries in today's interconnected world. In the past it proved to be a bad approach. For example, Roosvelt refused to declare war against Germany and was obliged to declare war to Japan after the susprise attack to Pearl Harbor in 1941.