Similarly, in the Lower House elections last December, which brought Abe back to power in an apparent landslide, the actual number of votes cast for the LDP was less than it received in the previous Lower House elections, when the party had been badly defeated. In other words, popular support for the LDP across Japan is more shallow and narrow than is widely understood.

Domestic politics and constitutional processes aside, as Aso acknowledged in his speech, the international context is also "complicated". Complicated indeed, because people in China, up and down the Korean Peninsula and throughout East Asia, Australia and the US are watching closely.

This is not a case of acting while "no one is looking", as Aso's Nazi allusion suggested. Surely an attempt to formally amend the Japanese Constitution would trigger vast international opposition. But that will not keep the LDP leadership from proceeding to achieve their objectives of constitutional revision by other means.

There is talk, for example, that future Supreme Court vacancies should be filled by judges open to revisionist interpretations of the Constitution. Also watch out for personnel changes in areas of government which handle constitutional affairs.

What the revisionists want broadly today are the same three major changes they have sought since the early 1950s. First, there is the matter of official rearmament. That means in effect renunciation of the stated intent of Article 9 of the Constitution, a provision that commits Japan never again to develop an offensive military capability.

Second, there is a series of revisions of the individual and human rights clauses of the Constitution, including the role of women in Japan's political system.

Third is an "enhancement", as the revisionists call it, of the status of the emperor.

Of the three, the latter is discussed the least in public, but in smaller circles this objective remains central to the nationalist right, as it has been since the "Peace" Constitution was adopted in 1947. It is in this light that one can best understand the symbolism of Prime Minister Abe's cry of "Tennou heika banzai!" (Long live the emperor) earlier this year during the first national "Restoration of Sovereignty" day ceremonies, in the presence of the emperor.

While the literal translation might seem commonplace in reference to a present monarch, it is actually the historical equivalent of "Heil Hitler" for 1930s Japan and has never been uttered by a prime minister in an official capacity since the collapse of the war cabinet in 1945.

It is not clear whether the emperor was happy with the invocation of the nationalistic exhortation from the wartime period of the 1930s and 1940s, but the nationalist militants were giddy with excitement at the prime minister's full-throated cry.

Aso was right. There are important lessons for Japan and the rest of the world to take from the sad experience of Germany's Weimar Republic - or indeed from Japan's own equally sad history.

But they are just the opposite of the lessons he is urging the Japanese constitutional revisionists to learn.

The author is managing partner of Starfort Investments, a former vice chairman of Goldman Sachs Asia and is a contributor to The Globalist, where this piece originally appeared.

The Globalist