The problem with Japan isn't fiscal. The problem with Japan is that Japanese men just aren't making Japanese women pregnant, and with barriers against both 'inter racial' breeding and immigration the population is not only in steep decline but is headed for extinction. No fiscal measures, however bold, can solve Japan's problem. Whilst the prospect of the Japanese people being wiped from the face of the Earth may cheer their old victims a bit, it does underline just how much comes down to population.
Before the start of the Great War, a representative group of ten Britons would have had six adults and four children. Now it would have eight adults and two children. We are living longer and having smaller families. And as the NHS champions 'healthy' living it's also storing up future costs; having eliminated many external causes of morbidity, if we all also lost weight and stopped smoking and drinking we'd bankrupt the Treasury in twenty years, even if we saved it money next year.
There are only two routes out of this. Import younger people who bear above average numbers of children to be future taxpayers, or correct the population balance. Only a lethal pandemic that strikes hard at anyone over 60 will effect the latter. With the highest population density in Europe, we've all but exhausted the potential for the former.
Without one or the other, the NHS in its present form simply can't continue.