In his best-selling book Soft Power, my friend and colleague Joseph Nye famously defined "soft power" as a state's ability to attract others to a set of "shared values and the justness and duty of contributing to those values."

Among other things, he saw the American system of higher education as a key source of this sort of attraction. Encouraging tens of thousands of foreign students to attend U.S. universities was an effective way to familiarize them with the core values of democracy, the rule of law, human rights, and free markets, and Nye argued that future elites educated here would be more inclined to share U.S. policy preferences. As former Secretary of State Colin Powell put it, "I can think of no more valuable asset to our country than the friendship of future world leaders who have been educated here."

I find this argument persuasive. Indeed, I once wrote: "the American university system remains a potent mechanism for socializing foreign elites. Students studying in the United States become familiar with U.S. mores while simultaneously absorbing mainstream U.S. views on politics and economics." (Full disclosure: over forty percent of the students at the Kennedy School of Government are from overseas, and I firmly convinced that helping to educate them is good for the world and good for America, too.)

From a parochial American perspective, however, this aspect of "soft power" has at least one downside. In addition to learning about American values and in most cases acquiring a more accurate and favorable impression of American society, some foreign students who study here also acquire an in-depth knowledge of how the American system of government works. They also learn how to talk to Americans in ways that we will find persuasive. In short, they gain a greater ability to manipulate our political system to their advantage.

For example, Georgian President Mikhail Saakashvili has a law degree from Columbia and also took courses at Georgetown. He has been something of a darling in hardline circles in Washington, and he was savvy enough to hire one of John McCain's foreign policy advisors (Randy Scheunemann) to lobby on Georgia's behalf. According to Stephen Sestanovich of the Council on Foreign Relations, these efforts gained Georgia a "broad base of support" in Washington. This is partly a testimony to Saakashvili’s own political skills, but his effectiveness inside-the-Beltway suggests that he learned a lot about what makes America tick while he was a student here.

A second example might be Ahmad Chalabi, the former head of the Iraqi National Congress and one of the key promoters of the U.S. invasion in 2003. Chalabi received a Ph.D. in Mathematics from the University of Chicago and proved to be unusually good at cultivating powerful friends in Washington. Indeed, his ability to sell bogus ideas about Iraq to gullible American neoconservatives suggests that he knew more about American than he did about politics in Iraq.

Then there's former (and possibly future) Israeli Prime Minister Benjamin Netanyahu, who went to high school outside Philadelphia and to college and graduate school at MIT. His fluid command of English and obvious familiarity with the American politics and culture have made him an effective media performer and a popular figure on Capitol Hill, where he testified in 2002 in favor of the invasion of Iraq. And let's not forget Prince Bandar bin Sultan, who received an M.A. in public policy from Johns Hopkins University's School of Advanced International Studies (SAIS) and served as Saudi ambassador to the United States from 1983 to 2005.

The United States is more susceptible to this sort of influence than most other countries for three reasons. First, the United States is a global superpower with commitments all over the world, and its leaders don't have time to master all the details of different regional situations. So when a smooth-talking foreign representative with lots of local knowledge shows up and tells us what he or she knows we'd like to hear, we are more inclined to buy it.

Second, foreign countries know that whatever the United States does will have a big impact on them, so they devote a lot of effort to shaping our perceptions in ways that will benefit them. If they are smart, they send their A-Team over here, and people who know how our system works and what buttons to press will be especially valuable. By contrast, we don’t have the time, energy, personnel or incentive to do that for the other 190-plus countries out there. Here it's also worth noting that the number of foreign students studying here significantly exceeds the number of American studying abroad. According to the Institute of International Education, there were over 600,000 foreigners studying here in 2008, compared with about 250,000 Americans studying overseas.

Third, the United States has a uniquely permeable political system. If a foreign diplomat can't persuade the State Department, Treasury, or Defense, there are 435 Congressmen and 100 different Senators for them to go to work on. As Ken Silverstein shows in his fascinating and funny book Turkmeniscam, there are also a host of lobbying and PR firms who are happy to help foreign governments sell their story here too. And someone who has studied here for a few years is bound to know a lot about how to do that more effectively than someone who has never lived here before.

This is not -- repeat not -- an argument for raising the drawbridge and keeping foreign students out. Knowing how our system works doesn’t enable foreign diplomats or government officials to dictate what the U.S. government does, and sometimes an all-out effort to bamboozle us will get nowhere, or even backfire. On balance, therefore, keeping our ivory towers open is almost certainly a net plus for the United States. And there's undoubtedly a positive-sum benefit when students from a variety of cultures come together to wrestle with common problems -- I see this every day in my courses. But let's not be naive: there are certain costs too, unless one wrongly assumes that foreign leaders will never, ever, try to get us to do something that might be in their interest but not in ours. And in those cases, an intimate knowledge of how American politics operates will give some foreign representatives an edge.

International politics is a competitive business, and it’s hardly surprising that other countries use their knowledge of the United States and its political system to try to advance their own interests. Instead of keeping foreign students out, however, perhaps the answer is to get more Americans to study abroad, so that we're as good at manipulating them as they sometimes are at manipulating us.

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