How NATO members are preparing for potential Baltic Sea battles

LONDON -- NATO troops, vessels and aircraft took to the frigid North Atlantic Ocean last month to sharpen their skills for a potential future war at sea, whether in the tumultuous Atlantic or in waters closer to their hypothetical Russian adversaries.

The drills -- led by U.S. Naval Forces Europe and the U.S. Navy's 6th Fleet -- "focused on the strategic waterways and airspace surrounding Iceland," a NATO press release said, an area it described as "a vital hub in the North Atlantic." NATO forces practiced tracking enemy naval forces -- including submarines -- and responding to mass casualty events.

But one part of the exercise was designed with a different region, though the same hypothetical enemy, in mind.

With U.S. Navy P-8 Poseidon aircraft acting as their eyes, Polish Naval Strike Missile (NSM) units used their time in Iceland to simulate strikes on enemy ships out at sea.

Lt. Bartlomiej Gryglewski, a liaison officer for the Polish navy's naval missile unit, told ABC News that his contingent performed every step up until the actual firing of the munitions. "We 'performed' a lot of strikes," Gryglewski said, describing the Norwegian-made NSM as a "pretty awesome" weapon.

The combination of the "precise missile" and the information gathered by the American aircraft above gives a "a high percentage chance -- almost 100% -- that the target will be hit," Gryglewski added.

The North Atlantic, though, is not the expected hunting ground.

"We almost always perform our exercises in the Baltic region," Gryglewski said, "protecting the Baltic Sea region from the enemy" as part of Poland's coastal defense system.

NATO's 'lake'

There, Russia is "facing a real imbalance" with its NATO rivals, Sidharth Kaushal of the U.K.'s Royal United Services Institute think tank told ABC News.

NATO's inclusion of Finland and Sweden -- a direct consequence of Russia's full-scale invasion of Ukraine in 2022 -- has prompted some officials to jokingly refer to the Baltic Sea as the "NATO Lake."

The trope "is a bit of an exaggeration, but only a bit," Kaushal said. "The maritime imbalance is significantly in NATO's favor, and that's a huge problem for Russia."

The Baltic Sea remains a key oil export route for Russian ships departing terminals in St. Petersburg. Commercial and military vessels alike must transit the sea to reach the Atlantic Ocean, passing through the Gulf of Finland and the narrow Danish straits with NATO eyes on all sides.

Russia's strategic Kaliningrad exclave is surrounded by NATO nations, its approaches in sight of the Latvian, Polish and Swedish coasts.

In the event of war, NATO aircraft and vessels could launch attacks on Russian territory from within the Baltic region that would "give Russian air defenses very limited warning times," Kashual noted.

"There's a whole range of conundrums that the alliance's preponderance in the Baltic Sea faces the Russians with," Kaushal said. "Reminding Russia of that fact is probably an important goal for the Americans, and for the wider alliance."

Russia's Foreign Ministry and the Kremlin have routinely criticized NATO military drills -- particularly those close to its border. In July, for example, Moscow hit out at NATO drills in Finland as "an integral part of NATO's comprehensive provocative efforts to contain Russia."

Control of the Baltic Sea is not a given for the Western allies. Russia's naval cruise missile bombardment of Ukraine from the Black Sea since 2022 has proved devastating, and proved that Moscow can "pose a real threat at depth across Europe," Kashual said.

"Sinking them early and demonstrating the ability to do so would be a real priority for regional countries like Poland, even if the aggregate balance of forces is now heavily skewed in NATO's direction in the Baltic," he added.

"There's a temporal question; can the Baltic Fleet be sunk in a manner that's both timely and cost effective before it's done an unacceptable level of damage across Europe with its cruise missiles?"

Polish NSMs, Kashual added, could prove to be "a big part" of NATO's answer to that question.

Poland's government has said as much. "Due to the reinforcement of the coastal missile units, manned and unmanned reconnaissance platforms, modern mine warfare and submarines, we will greatly increase our capabilities to protect our coastline," the Defense Ministry wrote in its 2032 plan.

Still, Western militaries may have to grapple with the same industrial strains that have so hamstrung Ukraine in its fight against Russia.

Advanced technology like the NSM may work well, but restocking munitions might prove a challenge. Last fall, the Polish Defense Ministry inked a deal with NSM producer Kongsberg Defence and Aerospace for "several hundred" more missiles.

Naval missile troops have plenty of active case studies to turn to. In the Black Sea, Ukraine has been able to hold back the Russian Black Sea Fleet, and even sink the Moskva flagship.

In the Middle East, the Houthis in Yemen have hit dozens of commercial ships and attacked Western warships in nearby waters. The group has even claimed to have fired on vessels in the Mediterranean Sea.

"I think that everybody at this time is getting some experience from those," Gryglewski said of the two ongoing conflicts. "But that's all I can say about this for the moment."