Dana Goward is president of the Resilient Navigation and Timing Foundation.

This week’s confirmation hearings for homeland security secretary and transportation secretary were notable for something not discussed: the fact that the two departments have failed for 12 years to comply with presidential orders to eliminate one of the most serious threats to the security and economy of the United States.

America’s Global Positioning System is a technological miracle and our gift to the world. Highly precise and free for use anywhere one can see the sky, the system’s timing and location signals have been incorporated into numerous essential technologies. Cellphone networks, first-responder radio systems, computer and financial networks, even electrical grids — all depend on GPS.

At the same time, GPS signals are weak and easy to disrupt. Illegal jamming devices are readily available on the Internet and are used by criminals, terrorists, even delivery drivers who don’t want to be tracked by their employers, to name just a few. Our national adversaries have no problems jamming GPS reception over large areas, and often do so. Solar weather can also be a problem, charging the ionosphere and preventing signals from getting through. Even poorly rigged television antennae can block GPS reception by reflecting signals and confusing receivers.

This combination of overwhelming dependence and vulnerability is why Department of Homeland Security officials have called GPS a “single point of failure for critical infrastructure.”

But, really, how bad could it be? Imagine what happens when GPS is suddenly no longer available.

Every mode of transportation immediately slows down, carries less traffic and experiences more accidents. Already-distracted drivers lose their turn-by-turn directions and become even more distracted. Similar problems arise in aviation and maritime travel. Making things worse, important aviation and maritime safety systems either shut down or provide bad information. Back on the ground, first responders have a hard time finding their ways to accidents, and their communication systems are either degraded or inoperable.

This horrible situation might not get much worse for the next half-hour or so. But soon, backup clocks in cellphone, computer, financial and electrical distribution networks start to lose synchronization with each other. Systems begin to degrade and fail. And because these infrastructure networks all rely on one another, a failure in one can easily cascade through several. The partial failure of a computer network, for example, might bring down some cellphone towers, ATMs and electrical systems. Once cascading failures begin, there is no telling when and where they will stop. Even if some peter out, over time more networks de-synchronize, and more failures spread. After a day or two, the nation could be nearly paralyzed.

But none of this is new information. In a 2004 national security directive, President George W. Bush tasked the Transportation Department to work with Homeland Security and other departments to acquire and operate a backup system to prevent such dire eventualities. President Obama reaffirmed this order in 2009.

Yet, despite announcements in 2008 and 2015 that the nation would establish a high-powered terrestrial eLoran system to work hand in hand with GPS, nothing has been done. So our national danger grows by the day.

Making the problem worse, Russia, China and Iran have terrestrial systems to back up their GPS and similar satellite systems. The United States not only is at great risk, it is at greater comparative risk than some of our adversaries and competitors.

Senior members of Congress and leaders within the incoming administration have been briefed on this danger to the nation. Retired Marine Gen. John F. Kelly, President-elect Donald Trump’s nominee for homeland security secretary, and Tom Bossert, Trump’s homeland security adviser, have both dealt with the issue in their previous government roles.

Yet, despite 12 years of failure to eliminate this potential “single point of failure,” no mention was made and no questions asked at confirmation hearings this week.

Previous administrations have understood the “single point of failure” problem and solutions, but have failed to act. The threat of a devastating solar flare, technical failure or terrorist attack, no matter how damaging, has always taken a back seat to what are seen as more pressing issues.

This problem could be solved fairly quickly with private investment spurred by a modicum of government leadership and participation. Let’s hope the Trump administration uses its focus on national security and private infrastructure investment to do what the previous two have only promised: protect America’s national and economic security with a difficult-to-disrupt complementary and backup system for GPS.