To get the industrial Midwest with its 140,000 steel workers to vote Republican in congressional elections, President Bush slapped a prohibitive tariff on imports of steel from Europe and Japan in 2001. He got what he wanted: a (bare) Republican majority in the Congress. But while the large steel users (such as automobile makers, railroads and building contractors) were forced by the tariff to buy domestic, they immediately set about cutting their use of steel so as not to spend more on it than they would have had to spend had they been able to buy the imports. Bush’s tariff action thus only accelerated the long-term decline of the traditional midwestern steel producers and the jobs they generate. Tariffs, in other words, can still force users to buy domestic, but they are no longer capable of protecting the domestic producers’ prices. Those are set through information and on the world-market level.
This development underlies the steady shift in protectionism: from tariffs–the traditional way–to protection through rules, regulations and especially export subsidies. World trade has grown spectacularly in the last fifty years. The largest growth has been in subsidized farm exports from the developed world: western and central Europe, Australia, Canada and the United States. Farm subsidies are now the only net income of French farmers, as their crops produce nothing but net losses and are grown only as the entitlement for the subsidies. These subsidies are in fact a major–perhaps the major–cement of the Franco-German alliance [TC: touche’, und Autsch!], and with it, of the European Union.
That is Peter Drucker, read more here.