Russia announced plans last month to build a submarine larger than its typhoon class, which is already the world's biggest nuclear-powered submarine.
The United States is also deploying a new generation of submarines, the Virginia class.
The U.S. Navy commissioned the world's first nuclear submarine in the 1950s, the USS Nautilus. It was actually the first nuclear-powered anything. Parts of it are even still classified.
Now it's open to visitors to explore and is moored next to the U.S. Navy base.
Just off the coast from here is where a Russian spy ship was spotted back in February. What were they looking for? Most likely the most efficient submarine squadron in the world and only on "CBS This Morning," CBS News correspondent Don Dahler gets a tour.
Despite the dolphins in their promotional video, the Navy's newest, fastest and quietest submarine is anything but playful.
The Virginia-class submarines can launch tomahawk cruise missiles, deploy a team of Navy SEALs from beneath the surface, and is among America's most lethal defense systems at sea.
"Submarines have come a long way since World War II," said Captain Brian Sittlow. He leads a squadron of submarines from the U.S. Navy base in Groton, Connecticut.
"The ocean more and more is becoming a very critical element of our national security and our ability to influence and ensure that our vital interests are protected throughout the world," Capt. Sittlow said.
And international waters are getting crowded. For example, a Russian sub got a Royal Navy escort through the English Channel last week.
Dahler asked, "Is the focus shifting somewhat given China's and Russia's interest in submarine development?"
"The focus is being more emphasized in controlling the world's oceans. Seventy percent of the globe is ocean. Over 80 percent of the world's commerce flows across that ocean," Capt. Sittlow said.
The U.S. Navy now has 69 commissioned submarines. Thirteen of them are Virginia-class subs, but that number will eventually double. Two are being built each year at a cost of $2 billion apiece.
On whether the hefty price tag is money well spent for the American public, Capt. Sittlow said, "Absolutely I do. Not only is it-- a price that we need to pay, it's a price we are paying and the capability that those ships bring-- is really remarkable."
The Virginia-class submarines, according to those who command them, are also incredibly efficient.
"We are able to make our own water. We make our own oxygen. We have a sustained fuel source in the nuclear reactor," said Commander Dan Reiss of the USS New Mexico, showed Dahler America's most modern submarine.
In the control room, Cmdr. Reiss noted, "And gone, you'll notice, are the periscopes."
"So the days of John Wayne and up scope and you know he's got his arm hanging over, they're gone now and they've been replaced with - entire periscope replaced with this joystick," Cmdr. Reiss said.
The view, can now be shared with everyone on board.
"During major events, for instance, during our homecoming, we were sending the imagery from the scopes all the way into the crew's mess so the sailor's could see the families on the coastline as they came up the river," Cmdr. Reiss said.
Back on base, sailors train with simulators and from land-locked control rooms.
Inside a 40-foot tower filled with 80,000 gallons of water, future submariners prepare for a worst-case-scenario escape from a disabled vessel.
The last time an operational submarine went down was in August of 2000. That's when all 118 aboard the Russian Navy Kursk died after a training exercise. Many believed it would cripple Russian resolve at sea. But their newest nuclear-powered submarine, the Kazan, was launched this March.
Still, says Capt. Sittlow, no country carries the international influence of the United States Navy.
"The United States, through our submarine force for nearly a hundred years now has gained and maintained a strong undersea advantage."