NATO is pouring concrete to support new 'battlegroups' in 4 countries amid rising tensions with Russia

• NATO is strengthening its presence on its eastern flank as Russia's attack on Ukraine continues.
• The alliance is setting up four new battlegroups in Bulgaria, Romania, Hungary, and Slovakia.

As Russia's attack on Ukraine continues, NATO has been strengthening its presence along its eastern flank.

Following an extraordinary NATO summit on February 24, the alliance decided to set up four new battlegroups in southeastern Europe. The four battlegroups, which are still being assembled, will be based in Bulgaria, Romania, Hungary, and Slovakia.

The new battlegroups will join the four that were established in Estonia, Lithuania, Latvia, and Poland in 2017 as a response to the deteriorating security situation in Europe following Russia's annexation of Crimea in 2014.

At its February summit, NATO also decided to strengthen its four northern battlegroups and "enhance the multinational battlegroups from battalions up to brigade size, where and when required."

NATO now has some 40,000 troops under its direct command in Eastern Europe — 30,000 of them in those eight battlegroups.

The battlegroups' sizes vary considerably: Hungary's has 900 troops, whereas Poland's has 11,600. The size and composition is "tailored to specific geographic factors and threats," NATO has said, but logistical demands and political factors also affect their makeup.

More than a tripwire

NATO has said that the establishment of the eight battlegroups is "the biggest reinforcement of Alliance collective defence in a generation."

The battlegroups are multinational forces permanently stationed in the host country and designed to operate alongside and strengthen that country's military in case of conflict. They are supported by units from NATO-member militaries that rotate through the host country but remain under the direct command of their home country.

The battlegroups' multinational composition is meant to deter Russia by making an attack on the host country an attack on all the NATO members with forces in the battlegroup.

The battlegroups will also act as a spearhead force, so they have to maintain a high level of readiness in order to buy time for reinforcements arrive in a conflict.

"We also felt the responsibility that we had as leaders of this spearhead battalion to demonstrate our capabilities to be ready, totally, with our Allies to fulfill the mission that we have been given," Lt. Col. Adrien, deputy commander of the Romania battlegroup, said in an interview about the battlegroup's first week.

In a conflict, the battlegroups would be reinforced by NATO's 5,000-strong Very High Readiness Joint Task Force, the alliance force with the highest readiness. The VJTF can start deploying within two days and would be followed by the NATO Response Force (NRF), which can start deploying within a week.

NATO is also expanding the number of high-readiness forces that can integrate with the VJTF and NRF. (A unit from a NATO-member military needs to achieve specific deployment speeds to be classified as high-readiness.)

Alliance members have further agreed to enhance NATO's ability to reinforce its forces along its eastern flank by pre-positioning equipment and developing more forward-deployed capabilities that would be needed in the opening stages of a conflict.

Not everyone is as ready

Russia still has working relations with NATO members Hungary and Bulgaria, which will host two of the new battlegroups. Hungarian Prime Minister Victor Orban is seen by some analysts as one of Russian President Vladimir Putin's closest supporters in NATO.

Hungary had refused to accept NATO troops, with its foreign minister saying before Russia attacked Ukraine that Hungary's military could defend the country.

Following Russia's invasion, Hungary was persuaded to host a few hundred NATO troops in a battlegroup that it would lead. Yet, these troops will only be stationed in western Hungary.

In February, just days before Russia launched its attack, Bulgaria's defense minister said the country would only accept a few hundred NATO troops for a battlegroup that it would lead and which would only conduct exercises.

Accommodating and integrating an influx of NATO troops is not easy, even for countries that are eager to counter Russia.

During a visit by high-level NATO officials to Estonia in September, Adm. Rob Bauer, the chair of NATO's military committee, said host nations need to ensure "that they can actually receive the troops, receive extra ammunition, receive extra vehicles, and make sure" they can build and support the facilities those forces need to train.

Estonia, which hosts one of NATO's four northern battlegroups, is currently expanding its military facilities to accommodate NATO troops, but it must find a balance between "in-place forces and forces which may come here, which are exercising the deployment here," Lt. Gen. Martin Herem, commander of the Estonian Defense Forces, told Defense One.

Estonia will also have to determine how many more permanent bases it will need. "But yes, I can say that, I don't think we need brigade-size units permanently here," Herem added. "I don't think it's efficient."

Estonia and its Baltic neighbors were part of the Soviet Union and have long warned about Russian aggression. They and other NATO militaries are now significantly boosting their military spending, partly to replenish the military supplies they've sent to Ukraine.

The efforts to improve NATO's readiness while continuing to support Ukraine reflect the alliance's view of Russia as "the most significant and direct threat to Allies' security and to peace and stability in the Euro-Atlantic area."

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