The advantages of isolationism is that you don’t have to be tangled up in any wars, except within your own country and if your nation is attacked. You save much money by not spending money on other countries problems and restoring them
Disadvantages when you need help in war you will most likely not have many people to help you because you were focused on your own country. A very big disadvantage of isolating your country is that if you trade with a country and you depend much on that source weather oil, food and clothing