One problem is by trading by sea, ships are bring invaise sea creatures to other countries and can harm the wild life for other marine ecosystems and for tons of people.
The person that answered previously isn't wrong but he also isn't entirely correct. A few problems are their monetary system, the fact that they might not have all the resources. Trade with other nations on land and sea. Taxes will be much higher for the people living their, also if their transit fails it could possibly lead to inflation
