In May of this year, the Department of Homeland Security (DHS) became concerned that terrorists may had been planning to exploit the U.S. visa system to enter the country and carryout an attack on the anniversary of 9/11.

That terrorists seek to exploit our visa system, of course, is nothing new. In fact, at least six of the 9/11 hijackers had overstayed their visas. What is surprising, however, is that this time DHS took smart and effective action.

Rather than pushing for more burdensome and largely ineffective policies (such as the 100 percent visa interview requirement), DHS instead chose to improve its system for determining if visa overstays pose a credible public safety or national security threat.

Using a new automated system, rather than manual checks, DHS was able to make its way through reviews of the roughly 1.6 million suspected overstay cases. In merely a matter of months, it was able to determine that about half, or 843,000, of these individuals had actually already left the country. Of those who remained in the country, it turned out that only about 2,000 needed further investigation.

DHS promises to be able to track the location of visa overstays within six to 12 months. This progress in measuring visa overstays is a promising step for U.S. public diplomacy and foreign relations. With better data on visa overstays, the Administration may finally be able to look toward expanding the Visa Waiver Program (VWP).

The VWP allows 36 member countries (that meet certain security requirements) to travel up to 90 days without a formal visa into the U.S., offering not only ease of travel for U.S. visitors but also added security, economic opportunities, and benefits in terms of public diplomacy. Nevertheless, since 2008 the expansion of the VWP has been hamstrung, leaving many key U.S. allies waiting on the backburner.

The delay is due to a congressional mandate linking expansion of VWP to the implementation of a biometric exist system to help determine when travelers overstay their visas. Yet hinging VWP expansion on deployment of a biometric exit system makes little sense.

DHS has repeatedly cited biometric exit as technologically and economically infeasible. Only a small number of VWP travelers actually become overstays—the very problem that biometric exit purportedly helps to prevent. In fact, the overall VWP participant overstay rate is estimated to be around 1 percent. So why are we hinging the program’s expansion and U.S. public diplomacy on an unrealistic and expensive measure that will provide little added security?

With the new system announced this week, DHS has proven once again that we can effectively track potential visa overstays without a costly and unworkable biometric exit system. So how much longer is Congress going to make our allies wait?