"We're the goalie for the U.S. and Canada," he said.
O'Shaughnessy went from defending a net as a goalie to defending a continent as a four-star general, leading the United States Northern Command (USNORTHCOM) and North American Aerospace Defense Command (NORAD).
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To put that in perspective, the Air Force has only about 10 four-star generals. USNORTHCOM protects the homeland, handling everything from military threats to natural disasters to disease outbreaks. NORAD is a binational organization of the United States and Canada that conducts aerospace warning, aerospace control and maritime warning for North America.
"The military's been doing some great work all over the world. But in the end, you have to have a good defense to make sure you're protecting things at home," he said. "It's an incredible honor and privilege to wake up every day knowing that my team and I are responsible for protecting the United States and Canada."
Hockey helped prepare O'Shaughnessy for his military career and has remained part of his life, even in places like Japan and Hawaii. When he spoke to NHL.com from Washington on Monday, he was going to see the New York Islanders and Washington Capitals play that night.
He will attend the 2020 Navy Federal Credit Union Stadium Series between the Colorado Avalanche and Los Angeles Kings at the academy's Falcon Stadium on Saturday (8 p.m. ET; NBC, SN360, TVAS, AFN|sports2), and he hopes people appreciate the cadets along with the players.
"They're dedicating their lives to serving their nation and volunteering to do that," he said. "I think it's just seeing the amazing men and women we have at the academy, getting a little bit of an understanding of what they're going through and what they have in their future."
O'Shaughnessy was born in North Bay, Ontario, but moved to Framingham, Massachusetts, as a kid. He played pond hockey with his friends and became a goalie after his father bought a set of pads at an auction. Though he was a Boston Bruins fan, with posters of Gerry Cheevers and Bobby Orr in his bedroom, a player from the rival Montreal Canadiens inspired him.
Goalie Ken Dryden graduated from Cornell University before playing in the NHL, then earned a law degree from McGill University in the middle of an eight-season NHL career that included six Stanley Cup championships and multiple individual awards.
"I saw Ken Dryden doing that, and it just kind of motivated me to not only play hard in hockey but do well in school," O'Shaughnessy said.
O'Shaughnessy played at Marian High School. The son of a private pilot, he also wanted to fly. The Air Force Academy offered the opportunity to chase dual dreams. Halfway through his freshman year at Air Force, he was called up to the varsity. Teammate Joe Doyle, now an Air Force associate coach, said he was "quiet in the room" and "really cerebral."
"He was one of us, but he was also way sharper than us," said Mark Manney, a teammate who would go on to fly Air Force One. "You could tell that his future wasn't in hockey. It was in doing great things with the military or whatever he pursued after graduation. It's a whole different level of smart."
O'Shaughnessy graduated in 1986 and became a command pilot with more than 3,000 hours in the F-16 Fighting Falcon, including 168 combat hours.
He said balancing the demands of a Division I athlete and those of a cadet taught him time management and work ethic. Hockey taught him teamwork -- putting on a uniform, counting on your teammates, making sure they can count on you, serving something greater than yourself.
He drew a line from the crease to the cockpit. You must have vision, think fast, anticipate. You never fly alone, relying on your wingman. You come up with a game plan, execute it and review your performance, constantly striving for improvement.
"Playing hockey and being a fighter pilot are so similar," he said. "The attributes that make you good at one make you good at the other. … For me, it was a real easy transition, to come out of the academy and then go and be a fighter pilot."
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As O'Shaughnessy rose through the ranks, sometimes he put on his skates. At Misawa Air Base in Japan, he played on the local city hall team. Hockey was a universal language.
"I didn't speak Japanese and they didn't speak English, but it was just great community relations to play with them," he said. "I skated out. It was a great time."
At Hickam Air Force Base, Hawaii, he played in men's leagues. He even played with one of his old Air Force teammates, Russ Quinn, 25 years after they played together at the academy.
"Believe it or not, there's actually a pretty good contingent of players in Hawaii," he said.
O'Shaughnessy doesn't skate anymore. But he's based in Colorado Springs, so he goes to Air Force games and talks to players when he can. He's proud of what the program is doing on the ice under coach Frank Serratore. He's more proud of what the cadets do, and will do, off the ice.
"It's just exciting to see their excitement and see they have their whole careers ahead of them," he said.
He's proof of how high they can fly.