Euthanasia is the practice of intentionally ending a life to relieve pain and suffering. Different countries have different euthanasia laws. The British House of Lords select committee on medical ethics defines euthanasia as "a deliberate intervention undertaken with the express intention of ending a life, to relieve intractable suffering". In the Netherlands and Belgium, euthanasia is understood as "termination of life by a doctor at the requestof a patient". The Dutch law, however, does not use the term 'euthanasia' but includes the concept under the broader definition of "assisted suicide and termination of life on request. As of 2006 euthanasia had become the most active area of research in bioethics. In some countries divisive public controversy occurs over the moral, ethical, and legal issues associated with euthanasia. Passive euthanasia (known as "pulling the plug") is legal under some circumstances in many countries. Active euthanasia, however, is legal or de factolegal in only a handful of countries (for example: Belgium, Canada and Switzerland), which limit it to specific circumstances and require the approval of counselors and doctors or other specialists. In some countries - such as Nigeria, Saudi Arabia and Pakistan - support for active euthanasia is almost non-existent.