The U.S. must invest more in its missile defense system to prepare for the growing and advancing threat of weapons capabilities as China and other nations start to acquire hypersonic weapon capabilities, a missile defense advocate told Fox News Digital.

"We're below one and a half percent of our defense budget on defensive capabilities," said Riki Ellison, former NFL linebacker and founder of the Missile Defense Advocacy Alliance. "That's pretty ridiculous. The most vocal is the Department of Defense because that's what it is. So, we are way off balance with lack of defensive capabilities."

Most people wouldn’t see missile defense as the next step following retirement from professional sports, but three-time Super Bowl champ Ellison, born in New Zealand, had worked for Lockheed Martin in Sunnyvale to work on the atmospheric re-entry system.

When he wasn’t training for the NFL, Ellison was working on the second-ever hit-to-kill intercontinental ballistic missile (ICBM) interceptor system. 

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"I was falling in love with the concept that we could shoot down mankind's worst possible weapon, and I [still] believe in that," Ellison said during an exclusive interview. After retiring from the NFL, he took a two-year sabbatical before returning to Washington, D.C., in the early 1990s to work on ground-based missile defense systems.

Ellison started working again at a time when missile defense systems took on a greater focus, and following a statement by then-President Bill Clinton that no country outside the five major nuclear powers – U.S., Russia, Britain, France and China – would develop significant ballistic missile capabilities until 2010, thus downplaying the threat that such weapons might pose.

The statement, made in the 1995 National Intelligence Estimate, prompted Congress to form the Rumsfeld Commission in 1998. The commission reached an opposing conclusion, stating that several countries were developing ballistic capabilities and claimed that the U.S. intelligence network wasn’t able to track the developments.

But the attack on Sept. 11, 2001, and the first North Korean missile launch over Japan caused a "critical shift" on missile defense.

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Ellison discussed a presidential directive to "deploy the first-ever ground-based interceptors in Alaska," which created a total 50-state defense, including the U.S. Capitol region, from cruise missiles. The technology took three years to deploy.

But Ellison realized that the U.S. had started to lose the "educational battle," prompting him to create his organization to combat that issue.

"My whole organization is built to support the deployment, the evolution of missile defense around the world because I believe that it makes the world safer," Ellison said. "There's no question it does."

His organization’s role has grown only more critical in recent years. China last year successfully completed the test of a hypersonic weapon – one of the key potential weaknesses in the U.S. defense structure as the U.S. lags in hypersonic development – and the world held its breath Tuesday when errant missiles struck Poland during a Russian attack on Ukrainian infrastructure, prompting Poland to invoke NATO Article 4.

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"I would say the last seven months have proved to the world your deterrence does not work against a near-peer," Ellison said, referring to other nations with similar missile capabilities.

"Your arms control agreement does not work against the near-peer, and the near-peer is using missiles to project their power because there is no missile defense capabilities out there to stop that, and they are setting the pace for the rest of the world that is watching this," he added.

The U.S. Missile Defense Agency, the section of the Department of Defense tasked with developing the nation’s missile defense systems, has a budget just shy of $10 billion for fiscal year 2023 – a number that sounds significant but amounts to roughly 1.3% of the Defense Department’s $761 billion budget.

Ellison argued that the military needs to determine the "roles and responsibility" of missile defense technology and that capabilities continue to grow at surprising rates – even dragging the conflict into the upper levels of the atmosphere, where ICBMs spend a significant amount of their flight time.

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"The bigger change, the bigger fights are going to be in space," Ellison said. He mentioned two projects in the 1980s called Brilliant Bubbles and Brilliant Eyes, as well as a more recent ballistic missile tracking system, that went up in space.

"These missiles are moving so fast that a land-based or air-based radar in the curvature of space flight fire before they can target it," he continued. "So, the only way to defeat the hypersonic missile is from space, because unless you know where that missile is going, you can’t do a terminal position."

"So, the first thing is, is that you have to have sensors in space and thousands of them or hundreds or thousands of [them], and probably all three different layers, so that, you know, every launch and every piece of space and can see it come in."

Ellison resurrected the idea of using a system akin to the proposed 1980s missile defense system "Star Wars," but with the twist that such a new system would utilize lasers since the lack of atmospheric drag would allow for greater efficacy. 

But Ellison worries that the lack of funding will make it difficult to reach those goals and leave the U.S. vulnerable as other nations catch up – especially after Pentagon officials have repeatedly raised concerns over the "pacing challenge" China poses. 

"The cheapest weapon to use right now is going to cost is $100 million per one ground-based interceptor in Alaska," he said. "How … are you going to compete with that?"

"I would say every single day people are dying because of ballistic missiles, hypersonic missiles and cruise missiles every single day, and … it's crazy because we have the capability to defend against all that stuff, but there's no capacity in any of these Western nations because [they all] chose not to pay the bill, thinking that deterrence and sanctions offense works," Ellison said.