 Failure to see the work of the invisible hand will lead to unwise policies.  Smith says that, in the absence of government intervention, self-interest leads each nation to produce only the goods in which it has a comparative advantage.  Self-interested behavior in the presence of government attempts to support domestic industries actually results in a worse outcome.  One goal of the book is admittedly practical: to attack mercantilism, the doctrine that dominated economic policy in Europe from the 16th century onward.  Mercantilism holds that aggressive government intervention is the key to increasing national wealth.  Accordingly, during this time, the governments of Europe attempted to steer and promote domestic industries, most notably by placing high tariffs on foreign imports (Palmer 1965, 102).  Smith argues against these policies. He writes that tariffs on imports harm the nation as a whole, by misdirecting its resources (1776, 485–487). In general, he says, the government should play a circumscribed role in the economic life of a country, confining itself to the protection of property rights, the support of a national defense force, and the provision of a few other key public goods (745). 