Relations with North Korea
http://www.investopedia.com/articles/investing/081715/2-countries-are-friends-north-korea.asp
This article gives insight into the countries that have good relations with North Korea. Russia, Bulgaria and China are countries that have notably strong ties with North Korea. While China is North Korea’s biggest trade partner, there has been tension between the two nations due to disagreements in nuclear weapon testing. The relation between North Korea and the United States has been hostile since the Korea War because of threats and differences in government rule causing Sweden to act as a mediator between the two nations. North Korea, being the most repressed country in the world with one-third of its population in the military, is looked down upon by the European Union and is not on good terms with a lot of countries.
We can apply structural balance to the relations between the countries by letting nodes represent countries and letting the edges represent the relation between the countries either positive or negative. An example of a structural balance would be the United States, North Korea and Russia. The United States has a negative or bad relationship with North Korea and Russia whereas Russia and North Korea have a positive or good relationship. This is balanced because two friends have a common enemy and satisfies the property of structural balance. Another example of a balanced structure would be the United States, South Korea and North Korea. The United States has a positive relationship with South Korea but not North Korea and South Korea has a negative relationship with North Korea. According to the property of structural balance this is balanced because for the set of three nodes there is exactly one positive edge.