After the second world, developing nations attained independence from their colonial masters, one of the reasons behind independence movements in colonies was that colonization stunted economic growth. There were different economic movements after this time to ensure independence(apart from humanitarian needs) didn't also mean failure for these nations. Modernization in this time was considered a tool for this economic development amongst various nations.
Nationalism is identification with one's own nation and support for its interests, especially to the exclusion or detriment of the interests of other nations.