Don't be too sure about that.
Prior to the Cold War, 1st World was Western Europe, 2nd World was predominantly the USA and Britain's "white" dominions (Canada, Australia, New Zealand). I'm not sure where South Africa fitted into the lexicon.
Earlier still, 2nd World was the Americas (north and south) in general.
These days, 1st world might mean those members of the OECH who have good public education and universal health care systems, while 2nd World are those OECH members without same -- sorry USA.
3rd World is everyone else -- non member of OECH, no universal health care system.
or is all that too serious for a "JOKES" thread?