Herod, exactly
KenV
Those boots have remained in Japan, Germany, Italy, (and in the UK, Korea, Kuwait and elsewhere)
No, you completely miss the point. The boots in Japan, Germany and Italy do not remain because of World War 2. They remain because of new threats from Russian (earlier Soviet), Chinese and N Korean threats after World War 2.
Also, hypothetically, there were no boots on the ground required in Japan after World War 2 because if the population and its leadership did not behave then a third, fourth, fifth, etc... bucket of sunshine could have been dropped - they had no defence against it. If boots had been committed to try and take all of the Japanese islands then it would have been utter carnage for both sides. Strategic airpower finished it and could have continued to finish it without the need for so called boots.
As for total war, don't be so sure. It doesn't take much for things to deteriorate into such carnage between allied states and/or religions. 72 years is a relatively short time in human history and our past history does not indicate to me that we should complacent that limited skirmishes are all we will ever face in the future.
LJ