Why hasn't any country tried to claim Antarctica?

This is due to the "Antarctic Treaty" which was signed in 1959 and which came to force in 1961. This Treaty was a result of Cold war so that no superpower could claim it. read more

These countries have tended to place their Antarctic scientific observation and study facilities within their respective claimed territories, but a number of such facilities are located nowhere near their country's sector and many nations such as Russia and the US have no claim anywhere in Antarctica yet have large research facilities within the sectors of foreign countries. read more

Antarctica is not a country: it has no government and no indigenous population. read more