Though people often use the term “Third World” today as a stereotype that suggests poverty and misery, in the middle of the century the concept...

The original concept of the "Third World" simply differentiated the world into three zones of influence: The First World, linked ideologically and economically to the United States; the Second World, linked ideologically and economically to the Soviet Union; and the Third World, which remained unaligned with either side.

Over time, the connotations of these words changed, especially after the fall of the Soviet Union. Today, the Third World largely means "underdeveloped nations" and mainly refers to central Africa, Southeast Asia, and Central America.

The more positive concept of the Third World as a group of nations rising up together against colonialist oppression is known as third-worldism. The basic idea of third-worldism is that the suffering and poverty of Third World countries is not due to their own flaws in governance or policy, but the direct result of ongoing colonialist oppression by First World and Second World powers.

Third-worldism is mainly associated with Mao Tse-Tung, the founder of the People's Republic of China. I would be remiss and historically negligent if I did not also mention that Mao was very likely the worst mass murderer in human history, and his disastrous economic policies based upon his delusional vision in the so-called "Great Leap Forward" killed at least 20 million people. By some estimates Mao is responsible for the deaths of as many as 70 million people.

That said, it would be guilt by association to dismiss the concept of third-worldism entirely based on this. It is possible that the basic ideas of third-worldism could be true, even given how horrifically Mao applied them.

Third-worldism really took hold as a meaningful driver of policy starting at the Bandung Conference in 1955, where representatives from 29 countries met to decide whether Third World countries should align with the First World and the USA, the Second World and the USSR, or neither.

Jawaharlal Nehru (the first Prime Minister of India) was a central figure in the Bandung Conference, and was a major influence on the ultimate decision, which was to remain non-aligned. Indeed, in 1961 he would go on to found the Non-Aligned Movement, which remains today as a group of over 100 nations that are united primarily by their... unwillingness to be united. Their concepts of universal human rights and national sovereignty are very similar to the United Nations, but they have far less power and influence in world affairs than the UN. Unlike Mao, Nehru was democratically elected and not a mass murderer---but many of his policy decisions were nonetheless quite dubious, particularly his commitment to import substitution and his botched attempts at land reform. He did, however, implement many beneficial policies, including public education and laws forbidding discrimination against women and ethnic minorities. 

Nehru's vision of "non-alignment" meant not only being separate from the major power blocs, but essentially being opposed to power blocs in general; Nehru believed in a decentralized world of many minor powers, none strong enough to dominate the others. As part of this project, he was strongly opposed to the stockpiling of nuclear weapons.

It is difficult for me to be sympathetic to third-worldism, because it appears to be largely responsible for the fact that "Third World" now means little more than "abject poverty". The political and economic policies that arose out of third-worldism were completely and utterly disastrous everywhere they were applied, and supported the entrenchment of some of the most corrupt and murderous tyrants the world has ever seen. By separating themselves from international trade, refusing to engage with "Western values" like democracy and free markets simply because they were "Western," and denying any responsibility to establish good governance and sound institutions in their own countries, Third World nations condemned themselves to remain in poverty and stagnation. It was only when some nations began to extricate themselves from these ideological chains that they finally began to see a rising standard of living---most clearly demonstrated by China, but also clearly true in India and many other countries. (Mark my words, we will soon see the same result in Cuba, now that the US has begun to normalize relations with them.)

Colonialism clearly did exist, and to some extent still does, and it has caused enormous damage; but rather than engage with all the causes of poverty and stagnation, third-worldism encourages people to simply scapegoat all problems onto colonialism and take no responsibility for actually fixing them.