They’re the sort of scores that drive high-school history teachers to drink. When NEWSWEEK recently asked 1,000 U.S. citizens to take America’s official citizenship test, 29 percent couldn’t name the vice president. Seventy-three percent couldn’t correctly say why we fought the Cold War. Forty-four percent were unable to define the Bill of Rights. And 6 percent couldn’t even circle Independence Day on a calendar.

Don’t get us wrong: civic ignorance is nothing new. For as long as they’ve existed, Americans have been misunderstanding checks and balances and misidentifying their senators. And they’ve been lamenting the philistinism of their peers ever since pollsters started publishing these dispiriting surveys back in Harry Truman’s day. (He was a president, by the way.) According to a study by Michael X. Delli Carpini, dean of the Annenberg School for Communication, the yearly shifts in civic knowledge since World War II have averaged out to “slightly under 1 percent.”

But the world has changed. And unfortunately, it’s becoming more and more inhospitable to incurious know-nothings—like us.

To appreciate the risks involved, it’s important to understand where American ignorance comes from. In March 2009, the European Journal of Communication asked citizens of Britain, Denmark, Finland, and the U.S. to answer questions on international affairs. The Europeans clobbered us. Sixty-eight percent of Danes, 75 percent of Brits, and 76 percent of Finns could, for example, identify the Taliban, but only 58 percent of Americans managed to do the same—even though we’ve led the charge in Afghanistan. It was only the latest in a series of polls that have shown us lagging behind our First World peers.

Most experts agree that the relative complexity of the U.S. political system makes it hard for Americans to keep up. In many European countries, parliaments have proportional representation, and the majority party rules without having to “share power with a lot of subnational governments,” notes Yale political scientist Jacob Hacker, coauthor of Winner-Take-All Politics. In contrast, we’re saddled with a nonproportional Senate; a tangle of state, local, and federal bureaucracies; and near-constant elections for every imaginable office (judge, sheriff, school-board member, and so on). “Nobody is competent to understand it all, which you realize every time you vote,” says Michael Schudson, author of The Good Citizen. “You know you’re going to come up short, and that discourages you from learning more.”

It doesn’t help that the United States has one of the highest levels of income inequality in the developed world, with the top 400 households raking in more money than the bottom 60 percent combined. As Dalton Conley, an NYU sociologist, explains, “it’s like comparing apples and oranges. Unlike Denmark, we have a lot of very poor people without access to good education, and a huge immigrant population that doesn’t even speak English.” When surveys focus on well-off, native-born respondents, the U.S. actually holds its own against Europe.

Other factors exacerbate the situation. A big one, Hacker argues, is the decentralized U.S. education system, which is run mostly by individual states: “When you have more centrally managed curricula, you have more common knowledge and a stronger civic culture.” Another hitch is our reliance on market-driven programming rather than public broadcasting, which, according to the EJC study, “devotes more attention to public affairs and international news, and fosters greater knowledge in these areas.”

For more than two centuries, Americans have gotten away with not knowing much about the world around them. But times have changed—and they’ve changed in ways that make civic ignorance a big problem going forward. While isolationism is fine in an isolated society, we can no longer afford to mind our own business. What happens in China and India (or at a Japanese nuclear plant) affects the autoworker in Detroit; what happens in the statehouse and the White House affects the competition in China and India. Before the Internet, brawn was enough; now the information economy demands brains instead. And where we once relied on political institutions (like organized labor) to school the middle classes and give them leverage, we now have nothing. “The issue isn’t that people in the past knew a lot more and know less now,” says Hacker. “It’s that their ignorance was counterbalanced by denser political organizations.” The result is a society in which wired activists at either end of the spectrum dominate the debate—and lead politicians astray at precisely the wrong moment.

The current conflict over government spending illustrates the new dangers of ignorance. Every economist knows how to deal with the debt: cost-saving reforms to big-ticket entitlement programs; cuts to our bloated defense budget; and (if growth remains slow) tax reforms designed to refill our depleted revenue coffers. But poll after poll shows that voters have no clue what the budget actually looks like. A 2010 World Public Opinion survey found that Americans want to tackle deficits by cutting foreign aid from what they believe is the current level (27 percent of the budget) to a more prudent 13 percent. The real number is under 1 percent. A Jan. 25 CNN poll, meanwhile, discovered that even though 71 percent of voters want smaller government, vast majorities oppose cuts to Medicare (81 percent), Social Security (78 percent), and Medicaid (70 percent). Instead, they prefer to slash waste—a category that, in their fantasy world, seems to include 50 percent of spending, according to a 2009 Gallup poll.

Needless to say, it’s impossible to balance the budget by listening to these people. But politicians pander to them anyway, and even encourage their misapprehensions. As a result, we’re now arguing over short-term spending cuts that would cost up to 700,000 government jobs, imperiling the shaky recovery and impairing our ability to compete globally, while doing nothing to tackle the long-term fiscal challenges that threaten … our ability to compete globally.

Given our history, it’s hard to imagine this changing any time soon. But that isn’t to say a change wouldn’t help. For years, Stanford communications professor James Fishkin has been conducting experiments in deliberative democracy. The premise is simple: poll citizens on a major issue, blind; then see how their opinions evolve when they’re forced to confront the facts. What Fishkin has found is that while people start out with deep value disagreements over, say, government spending, they tend to agree on rational policy responses once they learn the ins and outs of the budget. “The problem is ignorance, not stupidity,” Hacker says. “We suffer from a lack of information rather than a lack of ability.” Whether that’s a treatable affliction or a terminal illness remains to be seen. But now’s the time to start searching for a cure.