The relationship between Narendra Modi and Shinzo Abe has all the ingredients of a geopolitical bromance. The Indian and Japanese prime ministers are very keen on each other – and they do not mind who knows it. The two leaders shared a warm embrace over the weekend, as Mr Modi began a five-day trip to Japan. The Indian prime minister has even rhapsodised that Japan-India relations have “more potential than any other ties in the world”.

There are solid grounds for all this enthusiasm. The two men are both reformers who believe that their nations must embrace radical change if they are to shake off the economic gloom that has enveloped them in recent years.

The economies of India and Japan, although very different in development and structure, are also potentially complementary. India needs investment in manufacturing and infrastructure. Japanese firms have capital and high technology – and are looking for markets, labour and production bases. Although Japanese investment in India has, so far, been relatively modest it is increasing fast. There is, for example, a large Japanese stake in the Delhi-Mumbai industrial corridor – and $35bn worth of new Japanese investments in India were highlighted, during Mr Modi’s visit.