Prime Minister Shinzo Abe is a puzzling fellow. He has a whole host of immensely, intensely difficult political, diplomatic, economic and social issues to sort out, which he is tackling — let's be honest — not really very well. Yet now he has added a new, more contentious and potentially explosive problem, which he has declared he will solve by 2020.

Some supporters say he wants to claim his place in history — which is why he set so much store by winning the Olympics for Tokyo in 2020, and is getting the Liberal Democratic Party to change its rules so that he can still be prime minister in 2020 when Japan is host to the world.

Recently he has begun to talk with almost Messianic zeal about 2020, which he said would see the birth of a new Japan following revisions he wants to make to the Constitution. He should beware. Japan is a complex country carrying the heavy burden of history into a clash, and probably conflict, with its place in a complicated 21st century world.