DES MOINES, Iowa–responding forcefully to the ISIS attack on Paris, Donald Trump today said that as president, he would build a wall along the border between the United States and Europe to protect against threats from the Middle East, France, and Germany.

“If there’s one thing I’ve learned from the study of history,” said Trump, holding up a copy of Patton, “it’s that Europe’s problems will eventually affect us as well. Therefore the only practical solution to stop the flow of migrants and terrorists and waiters and high-end spa personnel is to build a wall at least thirty feet high all along our shared border.”

Asked how, exactly, such a wall would be built, Trump was dismissive. “That’s the kind of nitpicky thinking that got us in this mess,” he said. “I’ll have one of my business guys work it out.”

Trump also said that the wall wouldn’t cost American taxpayers anything, as he would force Europe and the Middle East to pay for it through levies on their major exports such as Lebanese cucumbers, French fries, and German measles.