Let's say in an ATL, where through the series of pure lucks and coincidences, the World's great powers manage to avoid a general war in 20th century. Over time, their interlocking systems of alliances are faded out. The four empires that in OTL were destroyed by First World War (Kaiserine Germany, Tsarist Russia, Austria-Hungary, and Ottoman Empire) gradually evolved into more liberal and democratic forms of governments, somewhat similar with their British and French counterparts. In East Asia, China eventually managed to modernize and industrialize itself, with strong helps and support from United States, who want to have a good counter for European and Japanese influence in East Asia and Pacific (proven by the fact that Chinese new republican government and constitution closely resemble that of the United States). Japan, though, successfully assimilated (or "Nipponified") both Korea and Taiwan to become integral parts of Japanese nation. Meanwhile, the United States becomes an economic and industrial great power of its own, although never to be a military superpower like it's in OTL.
Now, question: in this ATL, how would be the condition of OTL Third World, better or are they doomed to become backward regions like in OTL?
EDIT: So...certainly no WWI, WWII, Cold War, Russian Civil War, Chinese Civil War, Holocaust, Nazism, Fascism, Communism, Islamist Extremism, Terrorism, and most possibly no Arab-Israeli, Indian-Pakistani, and North-South Korean conflicts...
Is this the best of all possible world?