In my opinion, one of Steves Sailer's finest lines was his description of our disastrous national policy of "invade the world, invite the world, in hock to the world."
Obviously the Atlantic writers mentioned in Sailer’s blog post Emperor Hadrian insufficiently pro-Invade/Invite World have a globalist agenda. To these two writers, a border fence of course interferes with inviting the world and they fail to understand how free trade has made us more and more in hock to the world.[ The Great Wall of Texas: How the U.S. Is Repeating One of History's Great Blunders, By Glenn Hubbard and Tim Kane, July 9 2013]
It might interest you that the economist Ian Fletcher says he knows of no serious historian who believes Hadrian's Wall was a strategic mistake. As for the claim that protectionism caused the downfall of Britain, on the contrary, Fletcher wrote:
"Anyhow: Britain functioned on a mercantilist basis for centuries before its much misunderstood experiment with free trade began. Even as late as the beginning of the 19th century, Britain's average tariff on manufactured goods was roughly 50 percent—the highest of any major nation in Europe. And even after Britain embraced free trade in most goods, it continued to tightly regulate trade in strategic capital goods, such as the machinery for the mass production of textiles, in order to forestall its rivals. This was rational, as the win-win logic of free trade starts to break down if productive capital is mobile between nations or if free trade induces productivity growth abroad.A friend of mine is convinced that globalism is at the root of the immigration push. After all, we are told we need cheap labor in order to compete with China—ignoring the fact that we do not need to compete on their terms. Ian Fletcher wrote that globalism is not inevitable—it is a choice. And of absolute free trade. "It is not a conservative, but a libertarian and globalist policy."
After Britain embraced free trade in the mid-19th century, its long economic decline, of course, began. Today, the United States is making the same mistake, having mistaken the temporary tactical advantages of free trade for a nation at the peak of its economic power for a fundamental strategic truth. Meanwhile, our rivals, especially but not only in the Far East, hold firm to the mercantilist principles that we ourselves employed for 150 years." In Praise of Mercantilism (or Why Economic History Isn't Boring) Huffington Post, February 25, 2011
Unlike the Atlantic writers, I believe we desperately need a wall, we do not need to import cheap labor, and we can institute policies which will stop enriching China at our expense.