When the smoke finally clears on the ecological disaster now affecting large tracts of Southeast Asia, the cost is bound to impose a heavy financial burden on countries already beset by currency troubles and economic constraints. The toll that the fires have taken on the health of the 20 million people affected has been the main concern for the authorities so far. The immediate medical bill will be considerable. But there are medium to long-term implications which could prove more profound. The cost in grounded flights, cancelled bookings, failed crops, disrupted production and enforced closure of factories will have a knock-on effect lasting well into next year, perhaps longer. Export earnings from agriculture will be hit, in some areas significantly. In Indonesia, where the rupiah has lost a quarter of its value since the beginning of the year, officials are already reassessing economic forecasts. Inflation, they say, could rise to as much as eight per cent instead of their original five per cent target. Growth has been revised down two per cent, and an expected slump in tourism will make a big dent in tax revenue. Once the fires are doused, the world is left to contemplate an uncomfortable example of the chaos theory and how an event in one place can have repercussions beyond control. In their way, the fires graphically illustrate the inter-dependence of the region. A disastrous fire in one land has spread devastation abroad, so the efforts to rebuild from the ruins should also be a co-operative venture. The World Bank is prepared to provide funds if needed. But the most urgent need is for shared expertise and resources, and a new awareness of ecological responsibility of the kind proposed at the 1992 Earth Summit in Brazil. Many commitments were made in Rio, but few were kept. Perhaps the consequences of Southeast Asia's choking haze will help concentrate foggy minds.