A miliary veteran has hit the ground running in terms of helping other heroes.

John Barnett, a U.S. Navy veteran and retired New York Metropolitan Transportation Authority (MTA) police officer, has set out to run a marathon in all 50 U.S. states to raise awareness for local nonprofit Paws of War, which helps rescue and train service dogs for veterans.

The Long Islander enlisted with the Navy in 1986 and retired as a commander in 2011. Barnett continued his service with the MTA police department after he left the military, until an incident on the Fourth of July ended his career.

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On July 4, 2012, the officer was on routine patrol at the Long Island Railroad’s Jamaica Station when he was “ambushed” on the sidewalk, he told Fox News Digital in an interview.

The criminal, who had a knife, attacked Barnett — and stabbed him in the eye.

“I told him to drop the knife, and then I shot him,” he said. (See the video at the top of this article.)

Barnett underwent several surgeries to restore his retina — but his vision was beyond repair. 

He was left blind in his left eye. 

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“I’ve been retired ever since,” he said. 

Since the attack, Barnett has been receiving eye treatment and therapy for PTSD.

Barnett, pictured at center, was in “great spirits, laughing with colleagues as he left the hospital” after the incident, according to Paws of War. (Paws of War)

After the incident, Barnett noticed a sign outside Paws of War’s headquarters in Nesconset, New York, located less than half a mile from his house.

The sign mentioned that the organization helps America’s veterans and first responders.

“This is just my way of giving back and helping other first responders, brothers and sisters.”

“And I said, ‘Oh, well, I need to go in there, because I need help, and I’m a first responder — and a veteran,” he said. “So, I went in and they helped me out.”

Since then, Barnett said Paws of War has offered him “numerous” services, including veteran training for his two dogs, counseling and “camaraderie” within a community of other veterans.

Barnett has two service dogs, a German weimaraner and a German shorthaired pointer, both pictured here. (Paws of War)

While Barnett has always been an avid runner and has completed more than 30 marathons, the veteran decided to run for Paws of War to increase others’ awareness of the nonprofit and its good works.

“This is just my way of giving back and helping other first responders, brothers and sisters,” he told Fox News Digital.

“Everyone who goes through Paws of War has struggles, and if I can help one person, I feel good.”

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Barnett emphasized that the organization has helped him “significantly” through its various services.

“I would love for other first responders and veterans to receive the same help that I got from Paws of War,” he said. “By running, I can help others … This is my main goal. Just helping and giving back.”

Barnett said that listening to music, specifically to Steve Winwood or Elton John, while running a marathon helps him “feel great.” (Paws of War)

He added, “I think it’s one of the best services in the world for veterans and first responders.”

The Montana Marathon in Billings, Montana, on May 19 marked Barnett’s first run for Paws of War. His next race will take place in Anchorage, Alaska, on June 22 — which will mark his 27th U.S. state marathon.

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Although Barnett has run the New York City Marathon five times, he said his top two favorite marathons were in Burlington, Vermont, and Sugarloaf, Maine.

“Because you smell pine trees for 26 miles,” he said. “If you love the smell of pine trees, you’ll love that marathon.”

As Barnett’s goal is to get more veterans and first responders the help they need, he encouraged them to also reach out to their local VA hospital for immediate help.

“If I could just reach one veteran while I’m running a marathon and for them to reach out to Paws of War and say, ‘I need help’ — that would be great.” (Paws of War)

Paws of War co-founder Robert Misseri, who is based in New York, expressed his support for Barnett in a statement to Fox News Digital.

“John’s resilience and appreciation of giving back to Paws of War is another reason why we need to support our veterans and first responders,” he said. 

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“His efforts could save someone’s life.”

Paws of War’s mission, according to its website, is “to honor and support our veterans, active military members, and first responders with services that enrich their lives through the rescue and training of service dogs for independence, adoption of companion animals, rescue of overseas animals in war zones, and other essential services to assist our heroes in need.”