Not following you here -- Japan never had GSM, and even their initial attempts at 3G (FOMA, CDMA2000) didn't play ball with the rest of the world.
At the end of the day, the problem in the Western world was that operators were so in love with their massive SMS revenues with nearly 100% profit margins that they had zero incentive (well, negative incentive, really) to push for anything else. Whereas Japan, precisely thanks to not adopting GSM, never had SMS in the first place, so e-mail charged by the byte became the first killer cross-operator messaging app. (There were SMS equivalents in Japanese networks as well, but most all were restricted to one operator and consequently never really took off.)
Sure - what I mean is had Japan been the only place not to have GSM they may well have been forced to adopt it. GSM was around in the USA at that time (Moto Timeport "Worldphone" etc.) but was nothing like a standard, everywhere I looked I saw CDMA.
At the end of the day, the problem in the Western world was that operators were so in love with their massive SMS revenues with nearly 100% profit margins that they had zero incentive (well, negative incentive, really) to push for anything else. Whereas Japan, precisely thanks to not adopting GSM, never had SMS in the first place, so e-mail charged by the byte became the first killer cross-operator messaging app. (There were SMS equivalents in Japanese networks as well, but most all were restricted to one operator and consequently never really took off.)