Donald Trump’s latest call to build a border wall illustrates exactly why such a barrier wouldn’t stem immigration flows to the U.S. He has repeatedly called for a continuous wall along the U.S.-Mexico border to rid the U.S. of unauthorized immigration. The Republican presidential candidate’s first TV ad released this week features a cameo of one of the world’s most built-up border walls, and the choice is puzzling to political observers. First, reporters were surprised to learn that Trump’s team used footage from the border of Morocco and Spain, not Mexico and the U.S.

"No shit it's in Morocco,” Trump campaign manager Corey Lewandowski told CNN confirming the reports. “The footage was intentional. It's intended to demonstrate the impact of an open border [....] If we don't do something to build a wall and stop illegal immigration, that's what our country's going to look like."

Yet Lewandowski's team's intentions may backfire. If America’s southern border doesn’t look like that footage now, it’s because the Spanish-Moroccan border is closer to Trump’s border enforcement vision, not less.

“Donald Trump will stop illegal immigration by building a wall on our southern border that Mexico will pay for,” a baritone narrator declares in the Trump ad.

Yet the ad shows an example of one of the most intense border walls on the planet, a heavily fortified 7-mile fence between the Spanish enclave of Melilla and northern Morocco, which boasts stadium lighting, a double fence topped with razor wire and well-staffed army of border guards. It is a far cry from an "open border."

Also unlike Mexico, the Spanish authorities have some enforcement cooperation from their southern neighbors, who regularly round up and harass would-be migrants. Despite spending $40 million dollars just on the infrastructure of the Spanish wall, hundreds of migrants have succeeded in crossing that barrier.

In other words, Trump’s video broadcasts evidence that directly contradicts his theory that a fence can halt illegal immigration.