Groton — Rear Adm. Richard P. Breckenridge had been stationed in Groton three times before he became the leader of Submarine Group Two.

But, it wasn't until, as group commander, he said, that he listened to briefings from sub commanders returning from deployments and spoke with experts in special warfare and intelligence the group supports, that he realized that submarines — more so than probably any other element of the military — deter aggression from regional powers around the globe. Seventeen attack submarines deployed to hot spots during his 20-month tenure, from the waters off Libya to the Arabian Gulf and the North Atlantic.

"A lot of folks don't see that it really is our undersea force that prevents war — major war," he said. "And I didn't appreciate that as much before this tour."

Today, Breckenridge will turn over command of the group to Rear Adm. Kenneth M. Perry in a ceremony at the Submarine Force Museum. Vice Adm. Michael J. Connor, the commander of the submarine force, is the keynote speaker. Breckenridge is going to the Pentagon to lead the Undersea Warfare Division.

As the division's director, Breckenridge will help shape the future of the submarine force by figuring out where to invest and what capabilities to develop. He previously served as deputy director of the office.

His first priority will be to build a new class of ballistic-missile submarines to replace the aging Ohio-class boats, he said. He said he also wants to better articulate "our identity as undersea war fighters"— "who we are, what we provide and why it's of value."

"Part of my role in my next job is going to be to make sure that we have a recognition of the capability we provide, and by that I mean the real, meaningful deter war side of it, and the fact that we are potent if it does come to conflict," he said.

Submarine Group Two oversees all of the attack submarines on the East Coast, or 28 submarines currently. Six of those submarines are either under construction or at a shipyard for maintenance. The group is responsible for the ships and crews at Electric Boat and the Portsmouth Naval Shipyard.

Because of the highly classified nature of submarine missions, Breckenridge said he couldn't discuss what the 17 submarines that he deployed accomplished, but he did say they go where other forces can't, and the nation's adversaries "have to plan that we're there."

The USS Providence recently stayed at sea for more than seven months, instead of the typical six, because it was needed in the U.S. Central Command theater, which includes countries near the Arabian Gulf. Breckenridge said the deployment was extended for "vital mission tasking" and the crew did a "phenomenal job."

The U.S. Pacific Command is responsible for the waters near North Korea, not Submarine Group Two, so Breckenridge said he couldn't say whether any submarines are there. Submarines do typically covertly monitor activities by a potential enemy, he said, so "key decision-makers have the best picture of what's going on with the threat."

There are more than 300 submarines worldwide and a growing number of nations are expanding or modernizing their submarine forces, notably Russia, India and China, Adm. Samuel J. Locklear, commander of the Pacific Command, said Apr. 9 at a Senate Armed Services Committee hearing. Australia, Singapore, Indonesia, Malaysia, Vietnam and the Republic of Korea have recently launched — or soon will launch — new, modern submarines, he said in his testimony.

U.S. submarines need to deploy as often as they currently do so that allies can continue to rely on their contribution to regional stability, and other adversary navies don't eventually creep closer to the nation's coastline, Breckenridge said.

"We operate forward inside their 20-yard line, inside their red zone, so that they rarely come out into midfield and very, very rarely operate off the East or West Coast of the United States of America," he said. "I think the fact that we enjoy that advantage, where we don't have to go to bed at night wondering if there's going to be a land attack from sea, is something Americans have grown accustomed to and don't realize that it hasn't happened because we're out there."

The Special Forces, Breckenridge said, have "a good brand" and are well understood by America and Congress, but the public's comprehension of the role of submarines diminished in the years following the end of the Cold War because of the nature of the "silent service."

Revitalizing the submarine force's identity, Breckenridge said, will forge a closer tie with the public. Sailors leave their families to spend months at a time at sea and Breckenridge said he wants to make sure they know, and the American public understands, that they are making a profound difference.

Breckenridge often talks to sailors about the meaning behind the National Anthem. He tells them it's because "they stand the watch" that the chance of an attack on the homeland similar to the British bombardment during the War of 1812 is "much, much less."

"Our goal is to never experience the rockets' red glare within America in our lifetimes," he said. "It's our undersea force that contains potential overreach by the adversary through our superiority from the deep, thereby keeping the fight far away from our homeland."

j.mcdermott@theday.com