Holy shit maybe you should heed your own advice, hypocrite. The stakes are a lot higher with nuclear arsenals that can irradiate the world many times over. To equate the USA in 2015+ with Britain circa 1914 is a false equivalence, and there are many differences other than just nukes. The non-Britain-circa-1914 world is a lot different than the non-USA-in-2015+ world, too.
Let me put it this way: when was the last time 2+ members of the nuclear club got involved in a full-scale shooting war? If even Pakistan and India don't want to get into a conventional war that may spiral out of control, what makes you think China and the USA want to tussle? Exactly. The mere threat of Armageddon is thankfully enough to deter nuclear powers from attacking each other via conventional armies. Small skirmishes do still happen, but these days the nuclear powers mostly restrict aggression to espionage, cyberattacks, and economic competition. Sometimes they fund proxy groups, too, but even then they often try to present deniability, like Russia claiming that it didn't send soldiers to Ukraine.