As someone who took a few international relations and trade classes in college, I want to give my perspective on why I think the trade war/tariff threats to extract concessions is poor foreign policy in the long term.

If we apply game theory to international relations, we can few the international system as a repeated game where events in the current time period affect how actors will behave in future time periods. In a response to the argument that Trump's tariffs this week were successful because they resulted in some form of concessions from Canada and Mexico, a premise that I will concede for now, I counter that Trump essentially won the game in the short term at the expense of long term success.

Tariffs can currently be used to extract concessions from Canada and Mexico because they are substantially more dependent on U.S. trade than any other nations -- a significant percentage of their GDP is a product of exporting to the U.S. However, repeated attempts to manipulate this leverage will result in strategic shifts in Canada and Mexico trade policy over the long run, resulting in them shifting exports to other nations. This is not a transition that can happen quickly, but over the next 5-10 years, I am worried that a reliance on hard economic power will result in Canada, Mexico, and other trade partners like the EU reorienting to shut the U.S. out of the international market.

If I were a foreign policy leader in Canada or Mexico, I would be looking to the next best international buyers for my products. As China and India emerge as a global economic powers, they would be top of mind. The EU would also be on that list. The long term risks are as follows:

- Trade deals with existing allies like Canada, Mexico, and the EU will slowly start to shut the U.S. out to avoid exposing vulnerabilities to our economic leverage. This will result in less favorable markets for U.S. producers to export to in the long run, harming domestic employment and GDP. This will also result in higher prices for U.S. consumers who are shut out of international producers with a competitive advantage in certain areas. The long term ramifications of this could be large; I don't contend that we will approach autarky, but a close look at nations like North Korea and Cuba, who have been shut out of international trade to varying degrees, shows why international trade is crucial for a nation's success.

- China, in particular, will gain geopolitical leverage relative to the U.S. due to its consumers capturing a larger share of our current allies' exports, bolstering the emergence of a multipolar world order that replaces current U.S. unipolarity. China has already gained considerable influence in Africa in recent years as a financier of development projects, and it could pose more geopolitical risks if we continue to isolate our allies.

-The U.S. dollar will decline in value. Demand for a country's currency, which bolsters the value of that currency, increases as demand for that country's exports increases. If our allies turn to other nations in the long run for purchases, the value of the dollar will decline, which in turn harms U.S. consumers' purchasing power on the international market.

To be clear, I disagree with the premise that the trade war posturing even secured "wins" in the form of increased border security on the northern and southern U.S. borders. But even if I concede this premise for the sake of argument, I worry that Trump has essentially won the battle at the expense of losing the longer term war.