NATO's most vulnerable members are looking for backup amid tensions over Ukraine

• Amid tensions with Russia over Ukraine, the Baltic states are seeking more military support from NATO.
• Estonia, Latvia, and Lithuania are close to Russia and far from the rest of NATO, and Russia's military buildup near Ukraine has worried them.

The world is closely watching the Russian-Ukrainian border, where Moscow has deployed more than 100,000 troops and appears poised to reignite a conflict that has mostly simmered for the past seven years.

The UK has sent 2,000 anti-tank missile launchers and trainers to Ukraine, and the US is providing some 90 tons of weapons and ammunition to Ukraine's "front line defenders." Russia continues to bolster its forces in the area, including by moving troops and even ballistic missiles into Belarus — officially for joint exercises.

The situation has NATO on high alert, but three of its 30 members are watching events in Ukraine with particular concern: the Baltic states of Estonia, Latvia, and Lithuania.

Those three small countries share borders with Russia and a history of occupation and subjugation by their larger neighbor. Now strong democracies, they have looked to NATO for assurances of protection and are preparing themselves for the worst-case scenario.

A changing region

The Baltic Sea region was mostly uneventful during the Cold War. Non-NATO members Finland and Sweden remained neutral, while the Soviet Union, with its Baltic Sea exclave of Kaliningrad and its Warsaw Pact allies, including Estonia, Latvia, and Lithuania, dominated much of the rest of the sea.

The region remained relatively quiet after the Soviet breakup, but many of the countries there moved West — East and West Germany reunified, retaining the latter's NATO membership, and by 2004, all former Warsaw Pact countries in the region had joined the alliance.

Moscow's frustration at its loss of its influence after the Cold War has endured, especially after NATO's eastward expansion eliminated most of the traditional buffer between it and Russian territory.

Russia's seizure of Crimea in 2014 led to concerns that Russia could try a similar move against the Baltic states, which have been stoked by Moscow's rhetoric regarding those countries' sizable ethnic Russian minorities and territorial disputes with Russia.

The region has since become more militarized. After 2014, NATO set up battlegroups there, and the alliance's air-policing mission, ongoing since the Baltic countries joined the alliance, has reported a marked increase in Russian aerial activity in recent years.

Russia, meanwhile has set about turning Kaliningrad into a fortress as part of its overall military modernization efforts.

Russia's Baltic Fleet, which is headquartered in Kaliningrad, now has some 60 combat vessels, mostly small corvettes armed with missiles capable of striking targets 1,500 kilometers away.

Russia has also stationed at least 12 Iskander-M short-range ballistic-missile systems and dozens of S-300, S-400, and Pantsir air-defense systems in the exclave.

While it's not clear how many troops are stationed in Kaliningrad, Moscow has significantly expanded its military presence there in recent years. In addition to adding main battle tanks and other armored units, Moscow has also upgraded nuclear-weapons storage facilities and other installations in the exclave.

Kaliningrad is an important Baltic Sea port for Russia, but particularly worrying for the Baltic states is the possibility that Russia could use forces in Kaliningrad to cut them off from the rest of NATO by blocking the Suwałki Corridor, a 60-mile stretch of territory between Kaliningrad and Belarus that is also the border between Poland and Lithuania.

Increased defense and deterrence

In response to these challenges, the Baltic states have increased their defenses and urged NATO to do more.

NATO has maintained its battalion-size battlegroups in each country and in Poland, manned by forces from member countries on a rotating basis, and the Baltic States have repeatedly called for NATO to assume a larger, more permanent presence in the region.

In November, Latvian Defense Minister Artis Pabriks called for the permanent deployment of US military forces and Patriot missile systems in Latvia. In December, Latvian Foreign Minister Edgars Rinkēvičs called for an increased NATO presence on the alliance's eastern flank.

This month, Estonian Prime Minister Kaja Kallas called for a larger NATO presence to deter Moscow. "If you look at the map, the Baltic states are a NATO peninsula and therefore we have our worries," she said.

The Baltic states have also worked together and separately increased their own military capabilities. They are among the 10 NATO countries whose defense spending already meets the 2%-of-GDP goal that alliance members agreed to reach by 2024.

In December, the Baltic states issued a joint statement that, among other things, called for "joint development of regional interoperable Multiple Launch Rocket System (MLRS) capability," the creation of "a trilateral legal framework to enable rapid cross-border employment during peace time and crisis," and continued increases in defense spending.

Lithuania has since announced that it intends to speed up its acquisition of its MLRS by two years.

In addition to bolstering their own forces and calling for NATO to do more, the Baltic states have been steadfast supporters of Ukraine.

The three countries recently announced that they will send Javelin anti-tank missiles and Stinger anti-aircraft missiles to "further enhance Ukraine's capability to defend its territory and population in case of a possible Russian aggression."

In a joint statement issued at the time, the defense ministers from each state said that they "stand united in our commitment to Ukraine's sovereignty and territorial integrity in face of continued Russian aggression."