In the New York Times:
Over the past decade, some of the world’s leading democracies built walls and fences on their borders. The United States, India and Israel — often respectively described as the world’s oldest democracy, the world’s largest democracy, and the most stable democracy in the Middle East — built 3,500 miles of walls and fences; enough to stretch all the way from New York to Los Angeles.
All three countries contend that they are walling out terrorists. The Israeli government officially calls their wall the “anti-terrorist fence.” In congressional debates about the U.S. Secure Fence Act of 2006, supporters repeatedly linked the fence to terrorism, as Representative David Dreier said, “I hate the idea of our having to put up a fence. The fact of the matter is we have no choice. We have no choice because this week, as we marked the fifth anniversary of Sept. 11th, we are in the midst of a global war on terror. We face the threat of someone who would like to do us in coming across our border.”
In 2012, however, the war on terror is winding down. Osama bin Laden is dead. Many suspected Al Qaeda leaders have been killed or captured and are being held indefinitely in U.S. prisons. Suicide bombings in Israel effectively stopped at the end of the Second Intifada in 2005.
Although these walls and fences are among the most visible remnants of the war on terror, whether they are effective at preventing terrorism is debatable.