Two significant developments in the past several decades have been the collapse of communism as an ideology and the general acceptance, in rhetoric, if not practice, of liberal democracy.
In the 19th century it was basically nationality and people trying to define their nationalism and create states which would reflect their nationalism. In the 20th century, ideology came to the fore, largely, but not exclusively, as a result of the Russian Revolution and we have fascism, communism and liberal democracy competing with each other. Well that's pretty much over.
The West won the world not by the superiority of its ideas or values or religion […] but rather by its superiority in applying organized violence. Westerners often forget this fact; non-Westerners never do.
Fascism and communism have not entirely disappeared but have been sidelined certainly, and liberal democracy has come to be accepted, in theory at least, around the world, if not always in practice.
We really only came around to accepting and integrating the propositional dimension of identity into a concept of ourselves at the time of the American Revolution.