US warships went on another mission to a European hotspot, and Putin says they're in Russia's 'crosshairs'

• In early November, US Navy ships, including the Sixth Fleet's flagships, returned to the Black Sea.
• The visit is a sign of the US's increasing focus on the region, where NATO forces are spending more time.

On November 12, the flagship of the US Navy's Sixth Fleet, USS Mount Whitney, and Arleigh Burke-class destroyer USS Porter arrived at the Black Sea port of Constanta in Romania after visiting Batumi, Georgia.

The US warships were operating with NATO allies and partners in the Black Sea, according to the US European Command, and their deployment followed soon after US Defense Secretary Lloyd Austin visited the region.

Russia was incensed by that activity.

In a meeting with Russian military leadership, President Vladimir Putin seemed to threaten the US warships, saying Russian forces "can catch a glimpse" of USS Mount Whitney "through binoculars or through the crosshairs of matching defense systems."

Putin's comments come amid heightened tensions between Russia and NATO. Seven years after Russia's seizure of Crimea and with tensions simmering elsewhere in Eastern Europe, the Black Sea remains a hotspot — and it may heat up.

Transcontinental nexus

The Black Sea is in a strategic location, connecting the Caucasus with Europe along Russia's southwestern flank. It contains some of Russia's only warm-water ports and provides Russia access to the Mediterranean and the waters beyond.

The sea features prominently in Russian defense and security architecture because supremacy there is seen as vital for Russian security and for supporting power projection far from Russian shores. It also allows Moscow to challenge NATO.

The region "is the locus of the Kremlin's tests against alliance credibility and resolve, which have escalated over the last two decades in the conventional and nonconventional domain," Alina Polyakova, president of the Center for European Policy Analysis, a think-tank, said in October at a Senate hearing.

Those tests include close encounters with NATO forces at sea and in the air as well as attacks on Ukraine and Georgia, which are NATO partners seeking full membership.

NATO has stepped up its presence in the Black Sea — as shown by Austin's visit and the Sixth Fleet's exercises — but limitations of geography and international law mean countering Russia there is not a straightforward effort.

A Russian lake

After the Soviet collapse, Russia's Black Sea Fleet fell into obsolescence.

With Russia's 2008 military reforms and its 2011-2020 State Armament Program, the Black Sea Fleet became a lighter, more agile force able to operate in near-shore areas and surrounding waters.

The fleet's main elements are three Admiral Grigorovich-class guided-missile frigates built after the 2014 Crimean crisis, two Krivak-class guided-missile frigates, and its flagship, Slava-class guided-missile cruiser Moskva. It also includes six new Improved Kilo-class diesel-electric attack submarines and an older Kilo-class sub.

Those ships are supported by a host of smaller and auxiliary vessels, including six guided-missile corvettes and five missile boats, underlining the fleet's littoral capabilities.

The fleet is complemented by the newly formed 22nd Army Corps, one air-defense and two aviation divisions based in Crimea, and one air-defense division based in Rostov-on-Don.

Moscow is also enhancing its anti-access/area-denial capabilities in the Black Sea, particularly around Crimea, to protect its warships and hold off rival forces. Adding to the fleet's ability to strike at distance are 108 Kalibr sea-launched cruise missiles, which have a maximum range of approximately 1,200 miles.

NATO's Black Sea members and partners are at a military disadvantage when compared to Russia.

Romania has a navy of three frigates, seven corvettes, a handful of auxiliary boats, and an old Kilo-class submarine. Bulgaria does not fare much better, with four frigates, three corvettes, and a few support ships, most of them minesweepers.

Turkey has a sizable and capable navy, but its warming relationship with Russia and its estrangement with NATO have raised doubts about its commitment to the alliance.

Ukraine is rebuilding its naval force after the loss of Crimea, and Georgia, the smallest Black Sea state, has only a coast guard.

In a clash with Russia, those countries would likely seek outside help, but there are limits on what outside countries can do.

The Montreux Convention of 1936 restricts what kind of ships and how many ships non-Black Sea countries can send into the sea. It also limits their stay to 21 days, and Turkey must be given advanced warning of any transit into or out of the sea.

Those limits benefit Russia and hinder what the US can do. Only three of the US Navy's Arleigh Burke-class destroyers are allowed to be in the Black Sea at one time. But an Arleigh Burke is a powerful platform. Each can carry 56 Tomahawk missiles, which have roughly the same range as the Kalibr.

While two Arleigh Burkes could match the Black Sea Fleet's Kalibr complement, Russia watches their movements closely.

Adapting to a new landscape

Black Sea states, on their own and with NATO, are working to improve their ability to counter Russia, navigating the region's geographic and political constraints to do so.

Romania already hosts a land-based Aegis ballistic-defense missile system, and it's expanding other facilities to host more NATO troops. Bulgaria is working with the US to expand its military capabilities. Ukraine has taken a number of steps to modernize and expand its own military.

In the weeks since Austin's visit, officials in the region and US lawmakers have urged the Biden administration to do more to support countries there, including additional weapons sales and troop deployments. Others have advocated developing a clearer strategy for the region as a deterrent.

USS Mount Whitney began sailing out of the Black Sea on November 15, and USS Porter followed it out on November 16. Such deployments often raise Russian ire, but the US shows no sign of backing off, saying its presence there demonstrates "continued commitment to collective defense of the European region and reinforces the strength of the NATO alliance."

Constantine Atlamazoglou works on transatlantic and European security. He holds a master's degree on security studies and European affairs from the Fletcher School of Law and Diplomacy.