The Drug Enforcement Administration (DEA) is the most important U.S. federal body dealing with drugs, and it operates both at home in the United States, where it is principally concerned with fighting the distribution and consumption of drugs, and outside the United States, where it reinforces the national programs of other countries, in order to curtail the production or transit of drugs that may eventually end up in the United States. The United States is, by far, the most active country in waging a war on drugs; it also has the world's biggest drug problem in terms of consumption. Successive U.S. administrations have put huge efforts into fighting a war against the international drugs trade but, though they have registered successes in different parts of the world, the effect of these, as a rule, is rapidly annulled as a new source of supply springs up to fill the gap. U.S. strategy is to tackle the drugs business as close to the source as possible. The DEA, then, has two roles: domestic enforcement of federal drug laws and the coordination of U.S. drug investigations abroad.