Let me start by saying that fences on borders don’t appeal to my sense of libertarianism. In theory, fences limit freedom, and that’s a bad thing. Practically speaking though, fences work.
Here’s one lesson Americans can definitely draw from the Israeli experience of building a fence to separate them from the Palestinians: High fences don’t always make good neighbors. It didn’t happen in the West Bank, and it probably won’t happen in Texas. The country that builds the fence buys a sense of security, but the people prevented from getting to work, or shopping, or marrying someone on the other side will not be thankful for it. And the reason is pretty obvious: Fences work.
In Israel, the border fence with Palestine is great, from an Israeli perspective. I doubt Palestinians feel the same way.
As such, the Israeli fence is very efficient. The number of fatalities from terror attacks within Israel dropped from more than 130 in 2003 to fewer than 25 in 2005. The number of bombings fell from dozens to fewer than 10.
For a U.S./Mexican fence, the issue is not keeping out terrorists, it’s forcing immigrants to adhere to the rule of law. The United States does not have open, unregulated immigration – it cannot afford to with our current system of government. In a completely libertarian society, open borders might work. In our system of socialism lite immigrants must be controlled, monitored, catalogued, approved and processed. Most of us rely on government for our security. Many rely on government for medical care, retirement income and other vital services. In order to provide these things, government must control the population so it can plan ahead and manage. Uncontrolled immigration presents issues to national security and to the fiscal health of the country as a whole because our system of taxation cannot collect from unregistered immigrants as efficiently as it can from those of us who live “on the grid.”
Ultimately, the United States should embrace immigrants, and try to simplify the process of welcoming others to share in the blessings of being American. However, we must realize that not everyone who wants to live in the United States is good for the United States. Such people should not be allowed in, anymore than a private homeowner should be forced to accept a government assigned roommate who pays no rent and eats for free.
Bruce Schneier has a fascinating discussion on the idea of militarized walled borders going at his blog.
Whatever we do, there are no easy solutions. Open borders only work when you have good neighbors. People have been building walls to keep out their neighbors for millenia. I wish they were not necessary, but sometimes they seem to be the best solution when a neighbor isn’t playing nice.