We understand the importance of a nation keeping and maintaining a secure border. We know that the United States has been doing a poor job of keeping the its 2,000 mile border with Mexico secure, and that this has led to problems that President Donald Trump has promised to fix by building a wall that will be big, beautiful and better than any other wall ever built, with the possible exception of the Great Wall of China.

But we still don’t know how he plans to make Mexico pay for it, which was one of the top promises in his campaign. There’s not much leverage he can employ to make Mexico pay for a wall if it doesn’t want to.

Last week, Trump said a 20 percent tax on goods imported from Mexico would help pay for the wall. But Mexico wouldn’t be paying that tax. Mexican manufacturers and exporters would simply bump the price of their commodities to cover the tax. The people who purchase those goods — that is, American consumers — would be paying for the wall. It is an economic fact.

If the wall is going to be built, or even started, it looks like American dollars will be paying for it, one way or another. Which is not necessarily a bad thing.

It just puts the onus on the government to show the American public that this expensive project is really needed, and is really going to work.