This to me has always been one of those very visible signs (not certainties but signs in my opinion) of how nuclear weapons have changed the conduct of large na

This to me has always been one of those very visible signs (not certainties but signs in my opinion) of how nuclear weapons have changed the conduct of large nations. At most times in history before the advent of nukes, a geographical/political situation of a hugely populated major power being right below the vast, sparsely populated but resource rich territory of another large nation with a tenth the population would have absolutely resulted in a war of conquest and annexation by the former. Now it simply doesn't, partly no doubt because of international laws around wars of aggression and threats of international condemnation or economic sanction, but mostly I suspect just because the weaker power happens to be almost uniquely strong on having a shitload of nukes with which it can annihilate the other country regardless of the size of the latter's population, armies and economy. Before the 1940's Russia had no nukes and the two were in the same geographical situation, but China was then extremely weak, unlike now. Today's economic and political situation between the two translated to a pre-nuclear world would be very different I think.