It’s become a familiar sight: Kuala Lumpur’s famous skyline, dominated by the Petronas Towers, misted over as if in a watercolor; and in the streets, more and more people wearing surgical face masks. Those who stay outdoors for too long notice a smoky taste in their mouths, and then often complain of sore throats and breathing difficulties.  Welcome to Southeast Asia’s season of haze.  In Singapore, about 200 miles south, similar problems threatened the smooth running of the recent Formula One Grand Prix, a highlight of the island republic’s social and sporting calendar. All over Malaysia and Indonesia, schools closed, flights were canceled and politicians from each of the three countries engaged in finger-pointing and blame-shifting.  For the last two decades, a cloud of pollution has drifted over the region at this time of year, causing billions of dollars’ worth of disruption. The smoke originates in Indonesia, where large corporations and small landowners alike take advantage of the dry season to clear the land of forest and crops to make way for paper production or palm oil plantations.  The crude, cheap slash-and-burn method they employ has disastrous consequences over large areas, igniting peat in the soil to create fires that burn steadily over long periods. This year, weather patterns associated with the El Niño system produced unusually dry conditions, exacerbating the haze-producing fires.  That the haze affects millions in Indonesia is bad enough; but Sumatra, where the worst of the fires occur, is a mere 40 miles across the Strait of Malacca from the Malaysian Peninsula and Singapore, while Kalimantan, the other principal source of the smoke, shares a 1,200-mile land border with Malaysia. The resulting “transboundary haze,” as it is known, has placed mounting pressure on the Indonesian government to devise a long-term solution. And it has exposed the inability of the Association of Southeast Asian Nations to cooperate on cross-border issues that originate in one member state.  At a recent Asean meeting in Kuala Lumpur, an Indonesian member of Parliament in charge of international relations and environmental affairs issued a formal apology to Malaysia and Singapore for this year’s disruption. This echoed previous apologies made by Indonesian leaders, notably the former president Susilo Bambang Yudhoyono’s following the record-breaking 2013 haze.  For many Malaysians and Singaporeans, these mea culpas ring hollow, given the continued absence of any concrete countermeasures. Malaysia’s air pollution index assigns scores to common pollutant gases and particulate matter based on their concentrations in the atmosphere, and then gives an aggregate reading: A level of 101 to 200 is considered “unhealthy,” 201 to 300 “very unhealthy,” and over 301 “hazardous.” In September, the index in some parts of the country persisted above the 200 mark. In Singapore, readings peaked at 341, at one point casting doubt over whether the Grand Prix — including outdoor concerts by Maroon 5 and Bon Jovi — could go ahead.  Such jitters are not without a basis: In 2013, when air pollution levels in Singapore passed the 400 mark and the neighboring Johor State of Malaysia recorded a level of more than 700, the Singapore government estimated that increased spending on health care, together with disruption to air and maritime traffic, cost its economy $1 billion per week.  The blame, according to regional observers, lies in Indonesia’s failure to rein in the powerful corporations that run the increasingly lucrative palm oil plantations in Sumatra and Kalimantan. Rising worldwide consumption and booming prices have made the commodity a major contributor to the Indonesian economy — representing, by 2012, about 11 percent of the country’s export earnings, second only to oil and gas. Despite harsh penalties for those who break the strict land-clearing laws, there have been few successful prosecutions — which critics attribute to the plantation companies’ strong political connections.  Indonesia, meanwhile, claims that it is stepping up actions against those responsible. It cites the recent landmark conviction of the palm oil company PT Kallista Alam — fined more than $30 million for starting fires in Sumatra in 2012 — as proof that it is taking tough action to tackle the problem. Officials also hit back at criticism from their neighbors by pointing out that Malaysian and Singaporean companies also operate in the affected regions. At the height of the 2013 fires, the Indonesian minister in charge of the crisis accused Singapore of “behaving like a child.”  Much of the frustration felt in Malaysia and Singapore lies in the lack of institutional means to force Indonesia’s hand. Asean, which provides a forum for the region’s diplomatic relations, was formed on principles of national sovereignty and nonintervention — an approach that none of its members are keen to upset.  There was a small measure of progress last month when Indonesia agreed to share with Singapore a list of individuals and companies under investigation. This would at least enable Singapore to make checks on any that also operate within its jurisdiction.  Although there are no specific details yet, Malaysian and Indonesian officials have agreed to sign a memorandum of understanding outlining measures to deal with the fires in the future. Asean’s Agreement on Transboundary Haze Pollution, created in 2002, was ratified by Indonesia only last year; its wording does not confer on Asean any powers of enforcement. Last month, Jakarta again refused help from the Singaporean government in fighting the fires.  While the political tussles continue, Indonesia remains the worst victim of its fires, with pollution readings reaching a record high of 984 in the central province of Riau, where 26,000 cases of acute respiratory ailments have been recorded this season. As always during the haze, thousands of army and police personnel were sent in to combat the fires, and cloud-seeding operations were tried. But much like the skies overhead, the political way ahead for the region remains murky.  Tash Aw is the author of three novels, including, most recently, “Five Star Billionaire,” and a contributing opinion writer.  Follow The New York Times Opinion section on Facebook and Twitter, and sign up for the Opinion Today newsletter.
Air pollution from land-clearing fires has created a test of political cooperation that Indonesia, Malaysia and Singapore have yet to face.