Honolulu, Hawaii (CNN) Hundreds of feet below the surface of the Pacific Ocean, encased in some of the US Navy’s most technologically advanced pieces of equipment, Rear Admiral Jeff Jablon has a clear view of the two greatest challenges facing his team.
“In today’s world, we’re facing two nuclear adversaries where we’ve never had that before,” he said aboard the USS Mississippi, a nuclear-powered fast-attack submarine in the US Pacific Fleet.
“The Soviet Union – and now Russia – was our opponent in terms of nuclear capabilities. We are now facing China, which has expanded and modernized its nuclear capabilities.”
Earlier that day, the Virginia-class submarine had left its base at Pearl Harbor, Hawaii, and slipped beneath the waves into the world’s largest ocean on a routine mission.
About 130 sailors were at their stations throughout the ship, performing a variety of elaborate tasks.
The control room of the USS Mississippi, a US Navy fast attack submarine
More than a dozen sailors were on duty in the control room, some scanning the sonar for obstacles, others tasked with navigating the dark depths.
Technicians practiced loading weapons down in the torpedo room to be ready at all times, engineers manned the lower floors to ensure the water and hydraulic systems were working properly.
It is a cramped and claustrophobic work, in which the shipboard describes long periods at sea and intense relationships, almost like a family.
“I see them every day, work with them every day, sleep right next to each other,” says Jack O’Brien, a 22-year-old machinist from Massachusetts, of his comrades.
“And even when we’re in port, we work from dawn to dusk.”
AUKUS sub deal
As concerns mount over an accelerating nuclear arms race in Asia, a CNN crew was given exclusive access to the USS Mississippi, one of the 49 fast-attack submarines in the US fleet, according to Jablon, to witness Washington ramping up deterrence preparations a potential conflict in the region.
The role these ships play – difficult to detect, difficult to destroy and capable of long-distance travel – received new impetus when the United States, the United Kingdom and Australia released details of a nuclear submarine deal earlier this month announcements would see greater cooperation between the three countries to counter China’s rapid military expansion.
Under the so-called AUKUS deal, Australia will buy three Virginia-class submarines from the US in the early 2030s, subject to congressional approval.
China has criticized the deal, accusing the three powers of engaging in a “Cold War mentality” that will make the world less secure.
In November, the USS Mississippi made a port visit to the western Australian city of Perth, where it trained with members of the Royal Australian Navy, the US Department of Defense said.
The US and its allies have also raised increasing alarms about China’s growing military ambitions and territorial claims in the western Pacific and South China Seas.
Beijing’s ruling Communist Party has also refused to rule out the use of force in its conquest of Taiwan – a self-governing democracy of 23.5 million people that claims to be part of its territory despite never having governed it.
Last month, a CNN crew was aboard a US Navy reconnaissance plane over international waters in the South China Sea when a Chinese warplane flew in close proximity to intercept it.
“The National Security Strategy outlines that the PRC is our constant threat and Russia is an acute threat to our country,” said Rear Admiral Jablon, commander of the U.S. Pacific Fleet Submarine Force, using an acronym for the People’s Republic of China .
“The bulk of our submarine forces are now in the Pacific,” Jablon added. “Right now, about 60% of our (operational) submarines are in the Pacific because of these challenges.”
Despite the advances made by the Chinese military, experts say the US still has a significant advantage when it comes to underwater warfare.
“Submarines are one area where the United States has unmatched superiority over China,” said Carl Schuster, retired U.S. Navy captain and former chief of operations at the U.S. Pacific Command’s Joint Intelligence Center in Hawaii.
“They are the only stealth platform with the clout and survivability to counter the PLA Navy’s surface and underground forces,” Schuster said.
Impressive power
The Mississippi, like all U.S. Navy submarines, is nuclear-powered, giving her essentially unlimited range and time to deploy, requiring only visits to port to obtain provisions for her crew.
As Jablon put it, “All we need is food for individuals, and if we eat enough food, we could travel around the world without supplies.”
Firing nuclear-armed missiles is a mission reserved for the Navy’s 14 ballistic-missile submarines, larger ships often referred to as “boomers”.
But the USS Mississippi’s armament is still impressive – her class carries Tomahawk cruise missiles capable of hitting targets up to 1,000 miles away, as well as torpedoes to hit opponents on or under water.
When fully loaded, it can also carry up to 25 Mark 48 torpedoes — an advanced heavyweight torpedo that can hit opponents on or under water, said Edward Perry, the USS Mississippi’s commanding officer.
Jablon said the US submarine force has increasingly made its presence known to the general public and adversaries alike because of its deterrent effect.
“We were known as a silent service during the Cold War, (we) didn’t let anyone know where we were operating,” Jablon said.
“In today’s submarine force, we operate extensively with the rest of the United States’ agencies and with our allies. So the adversary knows that we can operate in international waters anywhere in the world,” he added.
China has massively expanded its navy in recent decades, but lags well behind the US in nuclear submarines, something Beijing is keen to change.
The number of Chinese ballistic missile submarines and nuclear-powered attack submarines, now numbering six each, is expected to more than double between 2020 and 2040, according to a 2022 report by the Congressional Research Service (CRS) on China’s naval modernization double.
Meanwhile, the PLA Navy is expected to maintain 44 diesel/air independent propulsion attack submarines, according to the US military.
Mike Sweeney, a graduate student at George Mason University, writes in the US Naval Institute’s Proceedings journal that there is a problem of numbers and size for US Navy submarines.
He says US submarine technology remains superior to China’s, but in a conflict with China “there may simply be a lack of sufficient numbers”.
Jablon, the rear admiral, gave some more details on how US Navy submarines are distributed.
Twenty-five of the fleet’s 49 attack submarines are based in the Pacific, he said. But some of those submarines — Jablon declined to give specifics — are unavailable for maintenance or other reasons, he said.
Some analysts say that could account for as much as two-thirds of the fleet.
“An old rule of thumb is that for every ship in service, two more are required – one preparing for deployment and a second retiring from recent operations,” Sweeney wrote in Proceedings.
Of course, China’s fleet would likely face similar maintenance requirements, but it only has to cover two oceans – the Pacific and the Indian – giving the PLA Navy an advantage in the total number of submarines in the Indo-Pacific.
Meanwhile, figures from the US Congressional Budget Office point to another potential problem for US attack submarines — the fleet is expected to shrink to 46 boats by 2028 before new construction programs ramp up, bringing the fleet up to 69 boats by 2052.
And last month, US Navy Secretary Carlos Del Toro told a budget appropriations subcommittee that construction of new Virginia-class submarines is “significantly behind schedule,” saying construction is proceeding at a rate of 1.4 submarines per year, well short of the planned two per year.
Away from loved ones
Life as a submarine operator can be different from other branches of the military.
Sailors meet March 29 aboard the USS Mississippi.
Because the submarine can be submerged deep in the ocean for long periods of time, the crew aboard the USS Mississippi must live in a small enclosed area with little communication with the outside world.
The crew is normally divided into three shifts to ensure the warship is manned 24 hours a day, explains ship’s Commander Perry.
The daily routine on board a nuclear submarine is largely standardized: crew members are on active duty for eight hours each day, followed by eight hours of studying, cleaning and socializing before they are forced to sleep.
“I think the greatest strategic asset of the United States is its people,” said Perry, who has served in the US Navy for 19 years.
“They are well educated, well educated, they have a lot of experience and they are patriotic. And so I think that when they put a ship like this out to sea, few people can replicate it.”
Steven Wong, a 26-year-old electronics technician from California, said he was a little shocked when he first joined the unit because of the limited space aboard a nuclear submarine.
“What surprised me the most was how close you get, that kind of shared difficulties and you end up with a really strong bond,” said Wong, who is in charge of operating the nuclear reactor to provide power and electricity.
Keeping in touch with loved ones is not an easy task considering how difficult it is to pick up signals in the depths of the ocean.
“The only time we can really communicate is via email at periscope depth,” said Wong, whose wife lives in Hawaii. “Every day I try to get to my unclassified computer to check my email. It always makes me happy when I see this unread message.”
CNN’s Brad Lendon contributed to this report