Thailand's behavior violates fundamental provisions of international human rights treaties to which it is a party, most notably the right not to be arbitrarily deprived of one's life. So why did the Thai government feel empowered to so callously disregard the rights of these migrants? The reasons are obviously complex, but one answer may be that international law governing the rights of migrants lacks specificity, particularly in this region. None of the states involved -- Bangladesh, Burma, Thailand, and even India, which is currently caring for the refugees -- is a signatory to the United Nations Convention Relating to the Status of Refugees. While the principle of non-refoulement may have attained the status of customary international law, the regional failure to join the Convention may contribute to a regional view that protection of refugees is a favor rather than a duty. And if the rights of refugees are seen as optional, then economic migrants have little hope of robust rights protection.
So what's the solution? Apart from encouraging nations in the region to ratify the Refugee Convention, a regional treaty that affirms that rights extant in international human rights treaties apply to migrants might help to change attitudes. Countries that produce large numbers of regional migrants could take the lead in promoting protection for their citizens abroad. The non-binding "Bangkok Principles" for the protection of refugees were a preliminary step, back in 1966 -- it's high time now to take the next.