The U.S. Navy formally re-established its 2nd Fleet on Friday, intensifying its focus on the North Atlantic Ocean where the Russian military is operating at a pace not seen since the end of the Cold War.

The change is mostly organizational. It revives an Admiral-level command dedicated to overseeing American warships as they deploy between the U.S. East Coast and the Barents Sea, off of the coasts of Norway and Russia.

The revived fleet also reflects a broader change in U.S. military strategy. The nation's primary concern is shifting from terrorism in the Middle East to America's growing competition with Russia and China.

"We're not looking for a fight," Chief of Naval Operations Admiral John Richardson said aboard the USS George H. W. Bush aircraft carrier in Norfolk, Virginia. "But the best way to avoid a fight is develop the most powerful and deadly and competitive Navy possible," he said.

Richardson added that if called upon, the Norfolk-based 2nd Fleet "will conduct decisive combat operations to defeat any enemy."

Both China and Russia are building larger navies as they try to expand their global influence. And Russia in particular has been increasing its submarine patrols, among other military activities.

In 2017, Russian Adm. Vladimir Korolyov said his nation's submarine crews had spent more than 3,000 days on patrol in the last year, matching the Soviet-era operational tempo. It's unclear how many days Russian subs had been on patrol in previous years.

"It's an excellent level," he said in remarks carried by state RIA Novosti news agency.

Concerns about information warfare have also emerged among U.S. lawmakers and American allies as Russian ships linger near undersea communications cables.

Encounters between Russian and NATO warplanes have also become increasingly frequent.

In January, Britain's Royal Air Force scrambled two fighter jets to intercept Russian strategic bombers near U.K. airspace.

The original 2nd Fleet was created in 1950 as a response to the growing threat of the Soviet Union. It played an integral role in events such as the Cuban Missile Crisis in 1962. It was eliminated and merged with Fleet Forces Command in in 2011 to save costs.

Having a 2nd Fleet allows the U.S. to work more closely and effectively with its NATO allies, retired U.S. Navy Admiral Gary Roughead said in an interview. And they will be better prepared to respond to potential Russian aggression.

Roughead said he fully expects the Russian military to increase its presence in the Atlantic in the coming years. One critical area will be the waters between the United Kingdom, Iceland and Greenland.

"Clearly, the Russian fleet is not the size that the Soviet fleet used to be, and nor is our fleet," said Roughead, a fellow at Stanford University's Hoover Institution and a former chief of naval operations. "But I think the reactivation is a very wise thing to do."