To win the war on terrorism, America must show the same self-confidence and courage that helped win the Cold War. We can start by throwing out visa policies that discourage foreigners from visiting their American relatives, going to Disney World or otherwise experiencing our wonderful country firsthand.

Currently, the U.S. has agreements with 27 countries that allow their citizens to visit us (and vice versa) for up to 90 days without having to get a visa. For travelers from these "visa waiver" nations, a simple passport is all that's required. This approach is a boon to tourism and business, bringing $75 billion to $100 billion a year to America, according to the Government Accountability Office.

It also boosts security. Visa waiver countries are long-standing allies. Trusting these friends to do due diligence when issuing passports frees the U.S. State Department (our visa-issuing agency) to concentrate its resources on screening visa applications from "countries of concern" - those known to harbor a sizable number of anti-American zealots.

By leaving the light on for foreign visitors, the visa-waiver program sends an important message: Unintimidated by terrorists, America remains an open nation, eager to welcome visitors to our friendly shores. It's a good program that should be made even better, and bigger.

The visa-waiver program hasn't been updated since 9/11. Many "Coalition of the Willing" nations - enthusiastic allies like Poland, the Czech Republic, Hungary and South Korea, which promptly demonstrated their solidarity with America in the war on terrorism - remain on the outside looking in.

Yet instead of opening the program to these tried and true allies, some members of Congress want to restrict or abolish it. They fear that terrorists will find it easier to slip into the U.S. from a waiver nation. Sen. Dianne Feinstein, D-Calif., calls the program "the soft underbelly of this nation."

Such alarmist rhetoric doesn't match reality. Tens of millions visit the U.S. every year. Yet the number of known terrorists who have tried to travel to the U.S. on visa-waiver passports is in the single digits. Not one of the 9/11 terrorists, for instance, entered in this manner.

Transnational terrorists have tried every conceivable method of travel - legal and illegal - to get here. The visa-waiver program has proved no less secure than any other avenue of admission, but has a long track record of promoting international commerce and goodwill. Unless we wish to seal our borders, shut off all transnational travel and become an isolated fortress America, ending this productive program makes no sense.

What does make sense is to reform it by requiring participating nations to meet more rigorous screening and approval standards. Some reforms - like requirements to check more rigorously for lost and stolen passports - are already in the works.

The U.S. should want more - not fewer - countries in the program, because they will be agreeing to abide by more stringent security standards for passport control and international cooperation.

Some visa-waiver opponents claim that opening the program will swell the number of illegal aliens in the country. "The more visitors we let in," they say, "the more people will overstay their visits."

Again, the fear is overblown. The vast majority of the 12 million to 15 million "illegals" currently in the U.S. came from Latin American countries that don't qualify for the visa-waiver program.

Moreover, there is a simple way to verify if visa-waiver visitors are complying with the 90-day limit. Congress already requires the Department of Homeland Security to conduct mandatory "exit checks" under the US VISIT program. Visa-waiver reform could jump-start the process by requiring that DHS conduct mandatory exit checks at the 11 major US airports that handle 70 percent of all international flights.

With this safeguard in place, new countries could enter the visa-waiver program on a trial basis. During the probationary period, their citizens would be required to leave the U.S. via one of these 11 airports. DHS exit checks would provide concrete figures as to how many visitors from these countries flout the 90-day limit. Countries with excessive overstay rates would be kicked out of the program immediately.

Visa-waiver expansion will send a message to the world that the U.S. is open for business, values its friends and allies, and is serious about thwarting terrorist travel. Implementing legislation that makes sense should be high on the congressional agenda.

James Carafano is a senior research fellow for defense and homeland security at The Heritage Foundation and coauthor of "Winning the Long War: Lessons From the Cold War for Defeating Terrorism and Preserving Freedom".