The insurgencies have their roots in historical forces and are often based on democratic values. Although the actions of the insurgent and terrorist organizations are justified, criticized, or analyzed on ideological or political grounds, most of the incidents are ultimately motivated by purely economic causes. As long as the region's profound economic problems are not resolved, political violence will probably continue and increase. The two main types of insurgency are wars of national liberation and revolutionary struggles based on social and political demands. Both leftist and rightist groups have used subversive and terrorist activities. The activities and their impacts have varied substantially from nation to nation. Finally, a creative, cooperative relationship is needed between North and South America if the underlying problems are to be solved and if a decisive shift toward populism, nationalism, and anti-Americanism is to be avoided even in the centrist nations.