REUTERS/Sergei Karpukhin
Russian servicemen drive S-400 air-defense missile systems through Red Square in Moscow during the Victory Day parade, marking the 73rd anniversary of the victory over Nazi Germany in World War II, May 9, 2018.
- Russian and NATO militaries are squaring off around Eastern Europe.
- While NATO forces are generally considered superior, some military planners worry Russian weapons could limit their ability to operate.
- The head of the Navy's newly reactivated Second Fleet is confident they can function in contested environments, however.
The Russian military and its NATO counterparts have been increasingly active in Eastern Europe, as the West moves to counter what they view as Russian aggression in the region.
One facet of Russian military activity that has been well noted by Western military planners is the expansion of anti-access/area-denial, or A2/AD, capability in strategically valuable areas.
Assets like the S-400 air-defense system - believed to be able to target aircraft from as far as 250 miles away, even the latest stealth aircraft - have been set up around Kaliningrad, which is Russia's exclave on the Baltic Sea, further south on the Crimean Peninsula and around the Black Sea, and on the Syrian coast, which provides a base from which to reach into the eastern Mediterranean.
REUTERS/Ints Kalnins US Army soldiers leave a Black Hawk helicopter during the Suwalki gap 
Surface-to-air missile systems deployed around Kaliningrad, which is tucked between Poland and Lithuania, were "layered in a way that makes access to that area difficult," retired Air Force Gen. Frank Gorenc told The New York Times in January 2016, when he was head of the US Air Force in Europe and Africa.
Those systems could affect NATO operations in Poland and the Baltic States, Gorenc said. (Russian forces using Kaliningrad to block the Suwalki Gap and cut the Baltic States off from the rest of NATO is a particular concern for the alliance.)
"There are varying degrees of capabilities" at each of those sites, Ben Hodges, who led the US Army in Europe before retiring as a lieutenant general at the end of 2017, told Business Insider at the beginning of November.
"But the one in Kaliningrad and the one in Crimea are the most substantial, with air- and missile-defense and anti-ship missiles and several thousands of troops" from Russia's army, navy, and air force, Hodges said. "That's part of creating an arc of A2/AD, if you will."
Associated Press
Three Ukrainian ships docked near the city of Kerch on the Crimean Peninsula on November 26, 2018, after being seized by Russia on November 25.
Russian state media said another battalion of S-4oo missiles had assumed combat duty in Crimea at the end of November, amid a state of increased tension with Ukraine over a violent encounter between their navies in the Black Sea.
Other air-defense systems, including the less advanced but highly capable S-300, are deployed in the region, including in the Black and Baltic seas. Other deployed A2/AD assets include coastal missile batteries firing anti-ship missiles.
When those systems - long embraced by Moscow to counter NATO's technical and numerical superiority at sea and in the air - are paired with electronic-warfare and radar systems, the concern is they could limit NATO's freedom of movement, especially in situations short of all-out war, when offensive options are restrained.
But "the alliance is alive to these challenges" and would "be prepared to use all the different things that would be required" in response to them, Hodges said, without elaborating.
Thomson Reuters A NATO flag flutters next to a US Air Force F-35A Lightning II fighter at Amari air base in Estonia, April 25, 2017.
Navy Vice Adm. Andrew Lewis, who recently took over the Navy's newly reestablished Second Fleet, which oversees the eastern half of the Atlantic Ocean, echoed Hodges during an event at the Center for Strategic and International Studies on November 28.
"Without going into things I shouldn't talk about, I'm confident that we can operate in an A2/AD environment, in a contested environment," Lewis said when asked about Kaliningrad and A2/AD. "In fact, I know we can."
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"I know we can with our carrier force. I know we can with our surface force. We have a very clear way of doing that. It is based upon maneuver," he added. "It's based upon physical maneuver. It's based upon maneuver in the spectrum, and it's based upon our ability to keep quiet when it's time to keep quiet and talk when it's time to talk."
There was still room for improvement, Lewis said, but he was confident US forces could get there.
"That's something that we're really, really focused on, and we have been focused on for a number of years now, and we're getting a lot better."