“It’s time for a debate about global interventionism,” writes the Cato Institute’s David Boaz, who hopes that Rand Paul will open the discussion on why peace and neutrality should be the United States’ cardinal principle.

“Historical data show a strong correlation between U.S. involvement in international situations and an increase in terrorist attacks against the United States,” according to a 1997 report from the Department of Defense. And as David notes:

In the end, bin Laden and al-Qaeda carried out another, far more devastating attack that left 3,000 Americans dead. In response, the United States launched two wars that lasted longer than World War II. We created the Department of Homeland Security and imposed huge costs on banks, air travelers, and other Americans. We transferred yet more power to the president and the executive branch. We erected vast, hidden surveillance systems. We undermined fundamental principles of individual rights, due process, and the rule of law. Economic costs of these measures will easily exceed $2 trillion, possibly several times that. These are just the sorts of costs of war that classical liberals and libertarians have long warned about.

Read more here from David Boaz, who cites from Thomas Jefferson’s first inaugural address: “Peace, commerce, and honest friendship with all nations—entangling alliances with none.”

And order David’s latest book, The Libertarian Mind, just published by Simon & Schuster.