economy: isolation in Edo Japan wasn't very good for economy. they could never trade out of there country because they closed out all the people who they could have traded with. since they couldn't trade they wouldn't have new goods or any new thing to try. they wouldn't get new food or new items they just had to use what they had in there country. it would be easy to attack Japan.
politics: with the isolation in Japan people might not be very happy .they might be upset because they aren't getting any imported goods from people from outside there country. so if the government weren't making the people happy everyone would be pushing for a new government. it would be hard for the government to stay in the position they are in. if you are isolated you cant ever really know if your getting attacked until it actually happens. if that in the battle everything gets destroyed the people of Japan would possibly get mad and rebel. they would want to get a new government.
social structure: merchants that weren't selling goods would be put lower in the social structure because they don't have any money (rice). if they get low enough they will be considered peasants. if peasants rebel they would get put into the outcast class. the outcasts don't get any attention and also live away from the city. isolation in Japan would be bad for the social structure. the samurai might get worried if everyone is losing money so they might get mad and start doing everything they can to not let that happen. they might even kill someone.