BANGKOK: An ill-defined border in one of the world’s most lucrative drugs producing areas is at the heart of tensions between Thailand and Myanmar, but recent skirmishes won’t lead to war despite centuries of enmity.

An attack by masked men in jungle fatigues on a Thai school bus killing three teenagers near the border this week has heightened emotions already raw from a series of bloody clashes involving Thai and Myanmar troops last month.

But the appearance of Myanmar patrol boats in disputed waters off southern Thailand last week, and thousands of troops on both sides of the border, is business as usual between the two uneasy neighbours, analysts say.

“This is 50 years and more of ups and downs in a volatile relationship, regular small-scale incidents that always have the danger of expanding into something more serious,” said Robert Karniol, Asia-Pacific Editor of Jane’s Defence Weekly.

But a broader conflict was extremely unlikely, he added.

Thailand and Myanmar accuse each other of supporting rival ethnic armies which produce much of the heroin sold on the streets of the United States and Europe and vast quantities of illegal stimulants.

MAKING MONEY: Myanmar’s ruling generals, seeking to bring all the country’s ethnic groups into a single union, say Thailand is arming the anti-government Shan State Army (SSA), successor to the notorious rebel army of former drugs baron Khun Sa.