In an age surely dominated by the machine (and the machine gun) what stands out instead about the era of Muscular Modernity was the rise of the subtly implied threat of old fashioned physical violence, used as a casual instrument of control by parents, teachers, bosses and competitors all through the Westernized world.
But only in one highly westernized part of the Orient, Japan, did this turn into the frequent and casual use of actual hands-on physical violence as a form of social control.
Only in Japan could one expect a superior officer to slap a junior officer as hard as they could, for some very minor problem, without anyone blinking.
And in no other country were officially authorized executions administered to victims so often by direct hands-on physical violence - by bayonet, knife, axe,swords, beatings - rather than by the indirect use of gun, rope or gas.
Perhaps it is worthy wondering if this behavior, rather than that of the much better known Auschwitz, might be the true culmination of 'Muscular' Darwinism....