These terms don't mean 2nd and 3rd tier countries. At least they didn't used to.
> The three-world model arose during the Cold War to define countries aligned with NATO (the First World), the Eastern Bloc (the Second World, although this term was less used), or neither (the Third World). Strictly speaking, "Third World" was a political, rather than an economic, grouping.
I actually didn't state anything about economic grouping. My point is the notion is dated - and you've illustrated that quite well with your comment. The eastern & non-aligned blocs dont exist any more & the first world has split into its own bloc-ish things, yet everyone is a lot more willing to play ball with each other than at any given time in history before.
> The three-world model arose during the Cold War to define countries aligned with NATO (the First World), the Eastern Bloc (the Second World, although this term was less used), or neither (the Third World). Strictly speaking, "Third World" was a political, rather than an economic, grouping.
https://en.wikipedia.org/wiki/Third_World