Excess isolationism also makes the economy more vulnerable. For example, primary industries are more exposed by gluts in production flooding the market and driv

Excess isolationism also makes the economy more vulnerable. For example, primary industries are more exposed by gluts in production flooding the market and driving down the value of goods, and shortages of domestically produced goods will obviously have a more severe impact on consumers. Obviously no protectionist scheme is going to tax goods that it's market cannot produce, but there is always a tendency to put industry above consumer, and assymetric/mercantile style protections in place. People often have intellectual debates about ideology/philosophy here, but nationalism is the real political force. If a government can be seen to steer its economy in the right direction, and its people feel well off compared to their neighbours, it will be popular, regardless of ideology, and regardless of how fairly it has treated other nations in trade negotiations. Likewise, a state will inevitably favor free trade when it will profit over other states, and protectionism when it won't. In the rare case when both states will benefit from an arrangement, there's usually some third party getting screwed, i.e. https://en.m.wikipedia.org/wiki/OPEC https://en.m.wikipedia.org/wiki/OPEC I'm conflating capital controls with trade, but my point is more that they are often negotiated at the same time, and in the with the same ultimately selfish and unideological outlook.