For Ricardo's theory of comparative advantage to work, a country's labor, capital, and technology must not move offshore
All the above are very mobile these days. Capital being mobile is always easy. But today We even have illegal immigration which makes labor mobile.
Technology is easily stolen, spread and diffused. Riccardo is good but these days with our massive international capital flows to the country with the best (hottest) investments, Ricardo is irrelevant these days
All the free trade theories are from a bygone age. The Orientals don't believe this illogical garbage. Go ask Korean, Chinese, Taiwanese, Chinese what they think. They practice mercantilism, not free trade