What motivated North Korea to attack South Korea?

In Korea, the Japanese government to build is based he nationalist ideology. In 1919 and 1925, communist Korea started the rebellion against Japan. Korea under Japanese occupation is considered as part of Empire of Japan along with Taiwan, which is part of the Regions Greater East Asia Co-Prosperity; in 1937, the Governor-General colony, General Minami Jiro, ordered an assimilation of Japanese culture of 23.5 million inhabitants colonies by prohibiting the language, literature, and culture Korea, and replace them with Japanese culture, and ordered the Korean people change their names into Japanese names. In 1938, government run colonial system of forced labor; to 1939, 2.6 million Koreans to work abroad as forced labor; in 1942,the men in Korea forced become Japanese soldiers.

My hypothesis is that the USA has inadvertently trained the North Korean government to act up and exhibit belligerence in return for inducements to behave! Yes, that's correct. I believe that as long as we offer aid, money, and etc. to countries we have difficulties with, the more often we will have difficulties.