ABOARD THE USS HARRY S. TRUMAN — Russia is flexing its growing presence in the strategic Mediterranean region by holding its first joint exercises with the Syrian navy, and the nuclear-powered USS Harry S. Truman — a 90,000-ton reminder of U.S. diplomacy and military might — is keeping an extra watchful eye.

The Truman carries more than 70 warplanes in nine squadrons, headed by dozens of F-18 fighter jets.

This week, its crews are monitoring the Russians as they hold the exercises from their only Mediterranean base and later this month conduct joint exercises with the Chinese and Iranians, as Russia’s TASS news agency has reported citing an Iranian naval commander.

With over 30 Russian warships in the area at one time, Adm. James Foggo, the commander of the U.S. Naval Forces in Europe and Africa, said the Russian presence in the Mediterranean is greater now than at any time since before the dissolution of the Soviet Union in 1991. Russian interventions in Georgia in 2008 and Ukraine in 2014 cast a continuing shadow over the Mediterranean and beyond.

“As long as they act that way,” Foggo said on the bridge of the U.S. carrier, “we’re going to be out here to remind them that there’s a cost and a risk to bad behavior and we won’t allow it.”

Sailors reset an aircraft catapult on the flight deck of the USS Harry S. Truman on Dec. 8. Thomas R. Pittman / U.S. Navy

In his annual press conference in Moscow on Thursday, Russian President Vladimir Putin claimed his country’s military progress “is very fast and powerful” as he praised the nation's growing defense industry.

Just five years ago, there was almost no active Russian presence in the Mediterranean.

The Syrian war changed all that.

The port of Tartus, Russia’s only warm-water naval base, became a hub for Russian forces fighting to keep Syrian President Bashar al-Assad in power.

For four years, Russian ships, aircraft and men have fought in and around Syria.

More than 63,000 Russian troops have served there, according to Russia’s Defense Ministry’s last year. The number today is almost certainly higher.

Russia has tested more than 200 weapons in the Syrian war, the ministry also said in its release.

But it’s not just in the Mediterranean that the U.S. Navy is actively countering the growing Russian presence.

In 2018, the United States had more naval presence in the Black Sea, a strategic body of water shared by Russia among other countries, than ever before.

This year alone, eight U.S. warships operated there, according to the U.S. Naval Institute.

Russian submarines and warships transit between the waters of the Black Sea and Northern Europe, and the Russians are operating with what Foggo calls “state-of-the-art nuclear submarines.”

“We still have the competitive advantage, but they are good and getting better,” he added.

Russian Navy's intelligence-gathering vessel Ivan Khurs sails in the Bosphorus, on its way to the Mediterranean Sea, in Istanbul on Nov. 29. Yoruk Isik / Reuters

In the most recent exercises in the Mediterranean, Russian state media reported that around 2,000 Russian and Syrian personnel took part, on about 10 ships, including mine-sweepers, and on warplanes from Russia’s Khmeimim air base in Syria. The Russian Ministry of Defense insisted that it’s necessary to constantly train the ship’s crews and coastal troops, Russia's Interfax news agency said.

And yet, at the heart of Moscow’s military might is a flaw.

Its only aircraft carrier caught fire in Murmansk last week. Also this year, 14 Russian sailors died in a nuclear accident on a deep-sea submarine.

Supporting the Truman in the Mediterranean are up to five destroyers, other support vessels and submarines. And high above the group, U.S. Navy Patrol aircraft scan the waters for threats both on and under the sea.

P8-A Poseidon aircraft during a training exercise over Naval Air Station Jacksonville on July 12. Levingston Lewis / U.S. Navy

The Poseidon P8 military aircraft is crammed with high-tech monitoring equipment, including sonic buoys that can detect its prime target — Russian nuclear-powered submarines.

“The submarine threats we face today are very different from those we faced in the Cold War,” Cmdr. Wayne Lewis said on board a P8 over the Mediterranean. “They’re more advanced than the old, diesel-powered vessels.”

Together with Russian surface vessels, the submarines comprise a powerful force.

“We’ve seen nothing but an increased presence from the Russian Navy,'' he said. “I’m not sure what kind of message they’re sending, but it’s not one of peace and prosperity.”