Nearly 35 years ago, then-President Ronald Reagan laid out a vision that dramatically changed how the U.S. viewed its national security. By reversing the strategy of “Mutually Assured Destruction” (MAD), he introduced a blatantly innovative idea that, at the time, earned laughter and derision from many in the political and national security elite. As it turns out, with North Korea threatening the lives of millions of Americans by flaunting its ballistic missile capabilities, Reagan was as prescient as ever.

“What if free people could live secure in the knowledge that their security did not rest upon the threat of instant Soviet retaliation to deter an attack, that we could intercept and destroy strategic ballistic missiles before they reached our own soil or that of our allies?” Reagan asked in his March 23, 1983, address to the nation.

It was immoral, he thought, to protect the peace by threatening to destroy humankind. With offensive weapons developed, he shifted the nation’s focus to defense, calling upon the scientific community to render the threat of nuclear-armed ballistic missiles “impotent and obsolete.”

Such a bold policy for missile defense was based on three sound principles. First, the United States rejects any notion of accepted vulnerability; second, we always operate from a position of strength; third, we recognize that the United States will never be secure if our enemies, like North Korea, will be able to use space as an avenue for an attack.

Thus, the Strategic Defense Initiative (SDI) was born. It became the keystone of a broader strategy that our 40th president had the vision to conceive and carry out that ultimately brought the Soviets to the negotiating table, ended the Cold War, and enabled the reduction of nuclear weapons for the first time in history. This initiative began a remarkable but topsy-turvy technological and political journey that created the nascent systems we have in place.

Today, we have space-, sea- and land-based sensors constantly watching for a missile threat. We have interceptors ready for instant launch and silos on the coast of California and farther north in Alaska to destroy a missile were one to be successfully launched at our mainland from North Korea or Iran.

But is that enough?

Lt. Gen. Sam Greaves, director of the Missile Defense Agency, has characterized our current challenge as one of modernity — or the lack thereof.

“The systems we have today were designed and deployed in a time when space was referred to as a sanctuary, as a peaceful place to be, where we were protected and no one would be able to get to us,” he cautioned in March 2016 at the Ronald Reagan Presidential Library. “But what we’ve seen in the last few years from our adversaries, space systems that were designed 10, 15, 20 years ago are now in direct threat of what these adversaries are doing.”

The evolution of our missile defense program and our commitment to it rises and recedes like a roller coaster. First funded, then defunded, redirected, refunded, then depleted, missile defense is today essentially in limbo.

As we neared the end of the Reagan presidency, the Strategic Defense Initiative Organization (SDIO) had developed a national missile defense concept that consisted of ground- and space-based sensors and weapons with a central battle management element. But in 1991, with the dismantlement of the Soviet Union, our focus was shifted to defend against limited missile strikes with defense coverage to include more local, theater range threats.

In 1993, President Clinton canceled the Ground-Based Mid-Course Defense System, which protected us against ICBMs. President George W. Bush asked for 44 ground-based interceptors to be built, but President Obama cut the program back to 30 within weeks of his inauguration. And the cuts have continued from there.

One of the most complex and advanced weapons systems ever made by the United States was the Airborne Laser, which mated a megawatt-class chemical laser and a Boeing 747 aircraft to destroy liquid and solid propellant missiles in their critical boost phase of flight. President Obama canceled it in 2011. By 2016, President Obama had cut at least $1 billion per year from Bush 41’s budget, with most of the cuts aimed at the “Ground-based Midcourse Defense” (GMD) system, our primary defense against North Korean ICBMs, along with the boost-phase interceptors.

“In the last several years, funding for missile defense has dramatically declined in some areas by as much as 60% and especially in the area of technology investment,” notes Lt. General Trey Obering, the former director of the Missile Defense Agency. “As President Reagan foresaw, the value of missile defense is now becoming crystal clear.”

Today, the real and imminent threat comes from North Korea. There is an urgency before us like never before in the modern day to increase the use of space, from sensors to interceptors, to counter enemy ballistic missiles. Investments in resiliency, data collection, increased ground computing power, increased radar power on the ground and in the air, and laser technology can help defeat the threat. Testing, in particular operational testing to simulate real-world combat conditions to assess the capability of our existing missile defense systems, is a must.

We need to define and fund a unified missile defense plan and support the efforts of those in Congress involved in forward thinking on missile defense. Sen. Dan Sullivan, R-Alaska, introduced a bill in May 2017 that would increase by more than 30% the number of interceptors currently in the U.S. The “Advancing American Missile Defense Act” is a direct response to continued aggression from North Korea and seeks to strengthen and improve the reliability, capability and capacity of U.S. homeland missile defense. It would authorize development of improved kill vehicles that intercept the warheads in space and order concept work on a space-based sensor layer that can track threats.

The Sullivan legislation has 27 Senate co-sponsors already. With very little bipartisan cooperation in Congress on the critical issues of the day, the development of a homeland missile defense system is a rare opportunity for like-minded, defense-conscious Republicans and Democrats to come together in defense of their country.

They must. It’s not a laughing matter anymore.

John Heubusch is the executive director of the Ronald Reagan Presidential Foundation and Institute and author of the new novel,The Shroud Conspiracy“.