Earlier this year when some Japanese train lines inaugurated women-only cars the Western media picked the story up as yet another example of Weird Japan, a place, they implied, where sexual deviancy was so culturally grounded that the only thing railway companies could do to protect female passengers from the wandering hands of salarymen was to segregate them.
Implicit in the coverage was the idea that such groping did not warrant the same sort of solution in the West, since it was assumed that women in other developed countries could take care of themselves under similar circumstances. I've often heard the same thing said by foreign residents of Japan who tend to think chikan (gropers) would disappear if Japanese women simply confronted them and fought back.
It isn't that simple, but in order to understand why it isn't that simple one must make a leap of imagination that is, in fact, culturally grounded.