South Korean officials have confirmed what the world hoped was a baseless rumor.
Refined plutonium generated by such a reactor can be used in the development of long-range nuclear weapons -- a decades-long goal of the Kim regime.
This development serves as a stark reminder that America must continue to invest in missile defense. North Korea remains bent on creating and possibly even launching ordinance capable of hitting the United States and its allies.
In light of the regime's longstanding propensity for erratic and highly irrational behavior, this goal clearly demands an American response.
But diplomacy has repeatedly failed to dissuade the regime. America is left to dictate the future of its own security.
Fortunately, modern missile defense technologies are capable of defending our nation against this mounting threat.
America's missile defense program is the brainchild of President Reagan. When he announced the initiative in 1983, critics dismissed it as pure science fiction, a "Star Wars" fantasy.
But since then, missile defense technologies have proven themselves time and again. These systems work.
The first major missile defense breakthrough came in 1991, during Operation Desert Storm. American soldiers successfully deployed the Patriot System to intercept incoming Iraqi scud missiles and protect allied military encampments.
Our soldiers saw the power of missile defense for the very first time. Since then, the federal government has poured serious resources into developing new technologies.
Those dollars have paid off. The American military now has a number of proven systems capable of detecting, tracking, and shooting down a wide variety of missiles.
In September, two medium-range ballistic missiles were successfully intercepted in the first operational test of new systems called Terminal High Altitude Area Defense and Aegis.
This display was all the more impressive because the sailors, soldiers, and airmen who conducted it were not given specific details about when or where the test would occur. It came out of nowhere. And the systems still performed flawlessly.
Then, in October, the latest version of the Ballistic Missile Defense system successfully intercepted a medium-range ballistic missile during a test.
The BMD runs on naval ships. It can be positioned close enough to global hot spots to counteract rogue missile launches, but far enough away from the action to keep our military personnel out of harm's way.
THAAD, Aegis, BMD and other systems are ready for action. And there are several more technologies in earlier stages of development that could prove even more effective than these three.
America needs these technologies now more than ever. The rogue missile threat has never been more acute — and it's growing each day.
It's not just North Korea. Rogue nations and groups that seek to enhance their international power can do so most readily through asymmetrical means.
They will co-opt militant groups to act as agents of conflict, utilize cyber warfare, and pursue weapons of mass destruction.
Indeed, Iran supports Hezbollah, regularly deploys its elite, disruptive "Qods Force," and actively pursues nuclear weapons.
This strategy has propelled it to the forefront of international politics and enhanced Iran's regional power in a way that mere conventional arms could not.
The United States needs to properly prepare itself. As the missile threat evolves, so must our capabilities. That means continuing to invest in both the refinement of existing, proven systems and the development of new, more effective technologies better matched to future threats.
Missile defense was once dismissed as a fantasy. It's now proven itself to be very much a reality. We have technologies that work. We must continue to develop them to meet the mounting missile threat.Rick Nelson is a senior associate at the Center for Strategic and International Studies, where he directed the Homeland Security and Counterterrorism Program from 2009 through 2012.