Even at the best of times, the Irrawaddy delta is one of the least accessible areas of one of South-East Asia’s most closed and impenetrable countries.

Roads are few and rough. Communication between the scattered farming villages is by boat along the myriad streams and channels known as the “mouths of the Irrawaddy”. The river sustains rich fishing and the most fertile rice fields in Burma.

However, early on Saturday — within the space of a few hours — the waters turned deadly.

It is too soon to know the extent of the destruction, but there is no longer any doubt that a massive humanitarian catastrophe has struck Burma. Cyclone Nargis, with its 120mph winds, coincided with a 12ft-high storm surge. Even last night there was little hard information about the extent of the damage but it seems clear that fields, houses, roads, ditches, houses and entire communities have been blown and washed away.

Yesterday morning, the official death toll was 351. On the state-run evening news it had risen to 4,000 and 3,000 “missing”. Two hours later, the military Government’s Foreign Minister was on state television. “According to the latest information, more than 10,000 people were killed,” Nyan Win said, after meeting foreign diplomats.

If the number of known dead increased thirtyfold yesterday, how much will it rise today?

The numbers of injured, it can be assumed, are several multiples of the dead. The numbers of homeless are unknown — the best that Richard Horsey, a United Nations official in Thailand, could guess was several hundred thousand “but how many hundred thousand we just don’t know”. A World Food Programme official said that 90 per cent of houses in the worst-affected zone were destroyed.

No one in Burma has seen a natural disaster like this in living memory. But this is a catastrophe whose consequences do not end with the dead and injured. Its ripples will be felt across the region and it has the potential, at least, to reshape the entire country.

Apart from the loss of life, the injuries and the destruction of tens of thousands of homes, the disaster may have far-reaching secondary effects. The flooding and destruction of sanitation systems increase the risk of epidemics, including malaria and typhoid; the loss of livelihoods is crippling in communities where many people subsist on less than $1 a day.

The features that made the stricken area vulnerable to this disaster — its low-lying geography and proximity to water — also made it Burma’s rice bowl. The cyclone has undoubtedly wrought terrible damage on the country’s agriculture. World rice prices are at a record high already, provoking food riots in more than 30 countries. Burma is a net exporter of rice, and the destruction of crops in the Irrawaddy delta will only add to upward pressure on international prices. The country may be unable to keep its promise to sell rice to other needy countries such as Sri Lanka and Bangladesh.

Last night international agencies were racing to mount South-East Asia’s biggest relief effort since the 2004 Indian Ocean tsunami. But they are powerless to act without an invitation from the Burmese Government. The Foreign Minister’s words last night suggest that this will soon be forthcoming — and this, in itself, represents a remarkable development for Burma.

The State Peace and Development Council, as the junta calls itself, is one of the most repressive and xenophobic dictatorships in the world. Last September it earned international odium by violently suppressing huge demonstrations by Buddhist monks and ordinary citizens demanding democracy. In the aftermath it expelled the head of the United Nations in the country and froze some UN activities.

The regime appears to regard foreign aid workers as a Trojan Horse, an encouragement and support to democratic subversion — but now, eight months later, it is poised to invite them in huge numbers.

On Saturday the junta is due to hold a referendum on a “democratic” constitution, which many Burmese regard as no more than a ploy to extend and legitimise the generals’ power.

After the arrest and persecution of those who took part in the September demonstrations, will the agony of the cyclone disaster cow the population even further? Or will it kindle further anger and lead to new unrest?

Already in Rangoon there were reports of local resentment at the failure of the military to assist with the clean-up. If these sentiments grow over time, and if the demonstrations start again, then Cyclone Nargis may turn out to have blown away much more than houses, fields and trees.

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