[lelio]

Please name one, just one, instance where trade barriers have worked to benefit a national economy over the long term?

The US? We had tariffs for most of our history.

[massadvj]

The US? We had tariffs for most of our history.

Actually, this is true, and a good point. Trade barriers are probably advantageous for countries with high growth rates. They benefited Japan, for example, in the 70's and 80's and they are benefiting China right now. But when the growth levels out, watch out. Japan is suffering the ill-effects of its trade barriers now, just as we suffered ours during the great depression.