Donald Trump today proposed a 20% tariff on goods imported from Mexico, saying that the revenue raised would effectively pay for the wall he proposes building along our southern border. It's quite apparent that Trump, and the people he has advising him, have little comprehension of how trade, tariffs, and international economics actually work. To begin with, there is every likelihood Mexico would go to the WTO (World Trade Organization) and lodge a complaint under its clause outlawing punitive tariffs. Never mind about NAFTA, Trump's tax would contravene WTO rules. Secondly, import tariffs are by nature levied upon the importer of goods. Not the exporter. For the very simple reason that it is much easier to collect money from someone in the United States. So inevitably the tariffs would be paid by US companies and individuals, and the associated costs passed on to their customers. The cost of Trump's wall will not be paid by wicked Mexicans, but by US consumers and businesses. Then there is the very strong possibility that Mexico may respond in kind by raising its own import tariffs on US imports. And here is the thing to remember: The entirety of Mexico's (and Canada's) trade surplus with the United States is due to oil and gas imports. Take Mexican gas and oil imports to the US out of the equation, and the US actually enjoys a current account trade surplus with Mexico. We sell them more agricultural products, machinery, farm equipment, fertilizers, etc. than we import Mexican car parts and avocados. If Mexico raised its tariffs in response to Trump's idiocy, then it will result in the loss of tens of thousands of US jobs in companies that export. This is merely the first salvo in Trump's war on our economy. Make no mistake, if he is allowed to proceed, he will plunge the entire planet into economic catastrophe that will make the 2008 crash look like a tiny bump in the road.