In the Spratly islands, a combustive mixture of oil, national pride and strategic influence is threatening to explode into open war between six powers with conflicting claims. China and Vietnam each claim them all, while Malaysia, Taiwan, Brunei and the Philippines claim part, and all save Brunei have troops there. 'They are the maritime equivalent of Bosnia,' said Gerald Blake, of Durham University's International Boundaries Research Unit. 'It is the single most dangerous dispute.'
Peking precipitated the flare-up by moving more troops on to one of the islands in defence of its claim. China and Vietnam have both awarded oil exploration contracts.
This is only one of a series of possible island flashpoints now that superpower influence is waning and regional powers are flexing their muscles. On the map we illustrate two dozen. Some are dormant, others resolved, but many continue to simmer, threatening to erupt in armed conflict.
In most cases the islands are uninhabited or have tiny populations, often predominantly military. Some have strategic importance because they dominate important waterways. Others bring the promise of wealth - in 1982, the United Nations Convention on the Law of the Sea legitimised 200-mile maritime economic zones.
Oil is at stake in the conflict between Bahrain and Qatar over the Hawar islands, which resurfaced in April when Qatar extended its territorial waters.
Mineral reserves are also involved in other disputes, potentially including the Falklands, where the intertwining claims of Britain and Argentina go back centuries, well before the foundation of the modern Argentinian state.
This dispute has also become bogged down in national pride, with regular military incidents culminating in the Argentinian invasion of 1982. Subsequently, the two sides have come to an accommodation, including co-operation over the region's rich fisheries. But Britain's decision to replace ageing Phantom fighters on the islands with Tornados shows that vigilance is not being dropped.
Fish have been a growing source of conflict in maritime disputes in the past two decades, precipitating tensions between Canada and France over the tiny French islands of St Pierre et Miquelon off the Canadian coast. These islands, home to a thriving smuggling trade during the Prohibition era, are entirely dependent on fishing.
The UN convention excludes 'rocks which cannot sustain human habitation or economic life of their own'. Some of these islands cannot really be considered anything more. Certainly, that was the Danish view of Britain's claim to Rockall, an outcrop in the Atlantic claimed in 1955 by the Royal Navy. In those days, no one had any thought for the sea-bed resources. But Iceland, Ireland and Denmark all dispute the 200-mile zone around Rockall. In 1985, to assert Britain's claim, a former Special Air Service member spent 40 days in a box bolted to the rock.
These disputes enlist all the panoply of nationalism, no matter how absurd. They trace their origins to voyages of discovery centuries ago, but for each one there are as many versions of the past as there are claimants. Since the first landings, most of the islands have seen dozens of invasions, counter-invasions, flags raised and lowered and plaques placed to commemorate ownership.
The end of colonial rule brought one wave of new disputes, in the Gulf, the Indian Ocean and the Pacific. Six are rows between France and Britain, which both retain networks of islands, and post-colonial states; these are the coaling stations and fortresses of maritime empires, now often home to military installations.
For 50 years, many claims and counter-claims were submerged by the hegemony of the United States and the Soviet Union, and many of the sovereignty battles we now face are the result of the evaporation of superpower domination.
The most potentially explosive disputes are in the Gulf, a flashpoint since Britain left in 1971, and the Pacific, where the decline of the Soviet Union and the departure of the United States from its Philippine bases has created a vacuum.
The resurgence of the argument between Russia and Japan over islands seized by Moscow at the end of the Second World War shows the complexity of these disputes. Russia claims that by signing the San Francisco Peace Treaty Japan gave up all claim to the Kurile islands. Japan says the San Francisco treaty is not relevant since Russia did not sign it, and that in any case, the disputed islands are not part of the Kuriles.
There are ways to sort out these conflicts without loss of face or resources; everyone can gain. A dispute between Argentina and Chile was successfully mediated by the Vatican; the Aland islands, home to a Swedish-speaking population, are peacefully part of Finland because of sensible policies in Helsinki. 'It shows that ways towards resolution of these problems can be found,' Mr Blake said. The Falklands dispute also seems to be moving this way.
But nationalism still holds the ring in most of the other disputes. The language of flags and plaques translates only too easily into rockets and rifles.