The rest of the world makes a useful distinction between a 'country' (such as France), a 'state' (the public institutions which run France), and a 'government' (the political entity which controls the French state).

However in the US the word 'state' is overloaded, so 'nation state' is used. It's confusing, because 'nation' is sometimes used to mean 'country' (which is how it's intended in 'nation state') and more traditionally used to mean a people with a shared language and history.