Xians claim that the US is ("was"?) a Xian country.
The response is that "the United States is in no way founded on the Christian religion," so of course not. There's even a Constitutional amendment interpreted to build a "wall of separation" between church and state!
Of course, both are ("were"?) true.
The US was not founded on Xianity nor does it have explicitly and avowedly Xian precepts as part of its organic law, so it's not a Xian country. That's "US as governmental system." The US population was self-described as Christian, so therefore it is a Christian country. The majority of the population was Christian, and to the extent a country has citizens those citizens were Xians.
Making such an obvious distinction--no matter how much it's a "minor nuance of no importance"--seems butt-obvious.
Is China a religious country?
Of course not, it's atheist. Of course, most of the population is religious.
Of course, then there's the second "nuance"--what's a "religion," since many of religions lack an obvious or explicit deity (or deities). Much of animism, Taoism, Confucianism (damned, almost misspelled that "Confusionism" , etc., etc., aren't "religions"--but adherents still want the symbols to be their religious identifiers on things like gravestones. (It's just that once you say a religion doesn't need a deity, it starts looking like a set of values + doctrines + rituals + organization + adherents, and some pretty religion-like secular organizations start serving the same roles with the same structures, and people start talking about them as 'secular religions,' which really pisses off those who insist that religions are evil but their own person values + doctrine + rituals + organization are in no way religions because religions are evil.)