New Delhi's nightmare scenario
The picture of Premier Wen Jiabao and Indian Prime Minister Manmohan Singh warmly greeting each other at the recent Asean summit in Vientiane told half the story. On the face of it, relations between India and China are at their best since the heady days of anti-colonial fervour in the 1950s.
China has helped wake India to the benefits of trade and competition. Regional power ambitions, officials realise, cannot be achieved on the back of a weak economy and self-exclusion from a competitive world. Indian commercial self-confidence has been growing, and with it a sense that it can compete not only against the developed world, but also China.
Both countries have recognised important common interests in the outcome of the Doha Round of World Trade Organisation negotiations. Both are anxious to prevent any backsliding from the forthcoming abolition of textile and garment quotas from which they will be the major beneficiaries. Both need to present a smiling face towards their Southeast Asian neighbours - although India lags way behind China, whose diplomatic flag is following close behind the rapid expansion of trade. Trade between China and India is itself now growing apace, albeit from modest beginnings.
The long border between the two remains quiet, and both nations have a common interest in countering the spread of Islamic fundamentalism, particularly from Pakistan into central Asia. As a result, both have been prepared to view with equanimity what they would once have vigorously opposed - the presence of US forces in Afghanistan, Tajikistan and Uzbekistan, for example.
However, behind all these immediate mutual interests lies a deep unease in India about the reach of Chinese power and its theoretical future ability to limit India's freedom of action in what it regards as its sphere of influence, and even threaten its supply lines.
There is talk about co-operation on energy issues. But the worry in New Delhi is that India is at least as dependent on imported hydrocarbons as China, but is in a much weaker position both commercially and militarily to secure its supplies.
In future, there is likely to be a shift in spending away from the ground, air and missile forces towards the long-neglected navy. Meanwhile, concerns about its own vulnerability partly explain its military co-operation with the US presence in the Indian Ocean, despite its criticism of the Iraqi war.
However, India is extremely uncomfortable with the US confrontation with Iran, which it sees as more driven by ideology in Washington than by US national interests. For India, Iran is a strategically important potential ally as well as the closest major external source of oil and gas. So it is viewing with concern China's growing role there. Chinese firms are engaged in major construction projects, and there is talk of a mega liquefied natural gas deal.
On it eastern borders, China's strategic presence in Myanmar has forced a shift in India's policy towards the junta, and China is also seen as attempting to build a relationship with friendless Bangladesh. It views with some alarm the expansion of China's nuclear submarine fleet. Others may think these are for deployment in the Pacific to threaten Taiwan and compete with Japan. But India fears they could become a factor in the Indian Ocean, too.
There is concern about the railway to Tibet, driven by strategic not economic considerations. Also worrying is any suggestion that Tibetan culture is part of Chinese culture which, by extension, has implications for India's ethnic Tibetan minority. China's attempt to appropriate Korean history has not gone unnoticed in India.
For now, things are rosy enough as each nation gives priority to economic issues. But longer term, India has plenty to worry about.
Philip Bowring is a Hong Kong-based journalist and commentator