On the wall in his office at Latvia’s Ministry of Defense, Undersecretary of State for Logistics Aivars Purins has a large map detailing every military facility in the country. These days the map features plenty of additional annotations: locations where Latvia is expanding its military infrastructure. It’s doing so to facilitate the presence of NATO troops.

Together with his counterparts in Estonia, Lithuania, and Poland, he plays a key role as the member states welcome the 3,000-4,000 troops NATO has decided to post there. “If someone called and said, ‘we want to permanently station troops in Latvia’, we’d go to extreme lengths to accommodate them,” Purins told me. “We’d even rent a hotel.” According to NATO statistics released earlier this year, the Baltic states spent 5-9 percent of their 2015 defense budgets on infrastructure, while NATO average infrastructure spending is around 1.5-2 percent of total defense spending or even less.

Baltic military spending is experiencing rapid growth. Last year Latvia’s defense spending increased by 14 percent, according to SIPRI (the Stockholm International Peace Research Institute) statistics. This year the government plans to spend 1.4 percent of GDP on defense and has said it will grow defense spending until it reaches the NATO benchmark of two percent of GDP by 2018.

At the Ādaži training range in central Latvia, the Ministry of Defense has already built new barracks with space for up to 600 soldiers.  Another barracks, which will also house up to 600 soldiers, will be finished in the summer of 2017. Two additional barracks with space for 900 troops will ready by 2018. A fifth one will be completed at Lielvarde Air Base, where the country’s air force is based.  The Ministry of Defense is also building a new shooting range, which will be completed next year. And specifically with the goal of supporting NATO troops, it is improving vehicle maintenance and parking infrastructure, administrative buildings, container areas and storage area.

Crucially, Latvia is also enlarging by one third the large and busy Ādaži range, improving ammunition depots, reconstructing tank ramps (which have not been used since the Soviets left), and improving access to railroads troops would need to use in order to transport equipment from the Baltic Port of Liepaja.

In Estonia, Undersecretary for Defense Investments Ingvar Pärnamäe told me that his ministry will build more barracks, maintenance facilities, a new building for NATO’s force integration unit, training areas, and ammunition storage facilities that can also store anti-tank and anti-aircraft missiles. Construction has already begun and will continue for the next several years.

Lithuania, too, is increasing spending on construction and refurbishment of military infrastructure. Among the construction projects now underway is a barracks for foreign military personnel at Šiauliai Air Base. Until now, Baltic Air Policing crews based at Šiauliai Air Base have stayed in the town of Šiauliai, some seven kilometers away. The new Šiauliai barracks, which will be completed next year, will have space for some 200 people and will feature a dining area and sports facilities.

Lithuania is also updating its roads. “Until recently, we hadn’t modernized the road networks in our training areas, but we’re doing that now, and we will also renovate the roads at our radar sites,” Lieutenant-Colonel Saulius Rožėnas told me. As Director of Logistics Department at Lithuania’s Ministry of Defense, Rožėnas is in charge of the country’s military construction. Last year, he explained, the ministry renovated 10 kilometers of roads leading through training areas and to radar sites. Road improvement is particularly important as NATO troops will bring tanks. Like Estonia and Latvia, Lithuania does not own battle tanks, but it is now modernizing old tank ramps in training areas.

Perhaps more significantly, the country is building facilities near Vilnius with space for a battalion-sized NATO presence. Rožėnas told me the facilities will be completed in 2018 and will include dormitories, dining facilities, and sports facilities, the common setup for military accommodation. In addition, the ministry plans to build RSOM capabilities. RSOM (Reception, Staging, and Onward Movement) is essentially temporary accommodation for troops and storage for their equipment as they pass through a certain area.

With armed forces comprising 118,000 troops – the new government has announced plans to increase the figure to 150,000 -- Poland faces fewer challenges than its Baltic partners in providing facilities for NATO troops. But it, too, is conducting an ambitious military infrastructure construction program. The Ministry of Defense is planning to renovate Cold War-era military storage facilities and upgrade roads.

According to the Ministry, it spent PLN 172 million ($45 million) on NATO-related infrastructure projects last year and will spend PLN 212 million ($56 million) this year. Last year, a Ministry of Defense spokesman also announced that the government would also spend PLN 300 million ($79 million, about a fourth which contributed by the United States) to modernize and enlarge the Drawsko Training Area, Poland’s largest; it will be used by both Polish and NATO troops.

The question now is how well, and how quickly, the four countries can complete the construction. The tight schedule, with most construction to be completed within the next three years even as troops maintain their regular schedule at the sites, makes coordination particularly challenging. Nevertheless, to date all projects have been completed as planned.

But large gaps remain. Neither the Baltic states nor Poland have fully modernized their ports and railways. This is an area where NATO member states and the host countries can jointly finance construction. And although USACE involvement is positive, the host countries have to consider what proportion of the projects use local labor and materials, which recycles the investment into the wider economy. The danger of handing large parts over to the USACE is that Congress will pressure the USACE to employ US contractors.

The host countries and NATO also have to reassure Russia of the new infrastructure’s defensive nature. Regular public updates about the construction – similar to NATO’s updates about its exercises -- would increase trust in NATO presence among the public and limit unnecessary tensions with Russia. Realistically, however, even such efforts would be unlikely to persuade the Kremlin of NATO’s peaceful intentions.

Another question is what the troop presence will look like in the longer term. Rotational troops arriving without their families add less money to the local economy than long-term personnel accompanied by spouses and children. But their costs to the deploying country are lower as there are no schools, married quarters, or family support facilities to be maintained. And perhaps most importantly, local populations have to be brought onboard. Most local residents approve of rotational troops training in their area, especially if the foreigners are joined by domestic forces. Foreign troops training on their own, however, evoke completely different feelings altogether: the specter of occupying forces. On the wall in his office at Latvia’s Ministry of Defense, Undersecretary of State for Logistics Aivars Purins has a large map detailing every military facility in the country. These days the map features plenty of additional annotations: locations where Latvia is expanding its military infrastructure. It’s doing so to facilitate the presence of NATO troops.

Together with his counterparts in Estonia, Lithuania, and Poland, he plays a key role as the member states welcome the 3,000-4,000 troops NATO has decided to post there. “If someone called and said, ‘we want to permanently station troops in Latvia’, we’d go to extreme lengths to accommodate them,” Purins told me. “We’d even rent a hotel.” According to NATO statistics released earlier this year, the Baltic states spent 5-9 percent of their 2015 defense budgets on infrastructure, while NATO average infrastructure spending is around 1.5-2 percent of total defense spending or even less.

Baltic military spending is experiencing rapid growth. Last year Latvia’s defense spending increased by 14 percent, according to SIPRI (the Stockholm International Peace Research Institute) statistics. This year the government plans to spend 1.4 percent of GDP on defense and has said it will grow defense spending until it reaches the NATO benchmark of two percent of GDP by 2018.

At the Ādaži training range in central Latvia, the Ministry of Defense has already built new barracks with space for up to 600 soldiers.  Another barracks, which will also house up to 600 soldiers, will be finished in the summer of 2017. Two additional barracks with space for 900 troops will ready by 2018. A fifth one will be completed at Lielvarde Air Base, where the country’s air force is based.  The Ministry of Defense is also building a new shooting range, which will be completed next year. And specifically with the goal of supporting NATO troops, it is improving vehicle maintenance and parking infrastructure, administrative buildings, container areas and storage area.

Crucially, Latvia is also enlarging by one third the large and busy Ādaži range, improving ammunition depots, reconstructing tank ramps (which have not been used since the Soviets left), and improving access to railroads troops would need to use in order to transport equipment from the Baltic Port of Liepaja.

In Estonia, Undersecretary for Defense Investments Ingvar Pärnamäe told me that his ministry will build more barracks, maintenance facilities, a new building for NATO’s force integration unit, training areas, and ammunition storage facilities that can also store anti-tank and anti-aircraft missiles. Construction has already begun and will continue for the next several years.

Lithuania, too, is increasing spending on construction and refurbishment of military infrastructure. Among the construction projects now underway is a barracks for foreign military personnel at Šiauliai Air Base. Until now, Baltic Air Policing crews based at Šiauliai Air Base have stayed in the town of Šiauliai, some seven kilometers away. The new Šiauliai barracks, which will be completed next year, will have space for some 200 people and will feature a dining area and sports facilities.

Lithuania is also updating its roads. “Until recently, we hadn’t modernized the road networks in our training areas, but we’re doing that now, and we will also renovate the roads at our radar sites,” Lieutenant-Colonel Saulius Rožėnas told me. As Director of Logistics Department at Lithuania’s Ministry of Defense, Rožėnas is in charge of the country’s military construction. Last year, he explained, the ministry renovated 10 kilometers of roads leading through training areas and to radar sites. Road improvement is particularly important as NATO troops will bring tanks. Like Estonia and Latvia, Lithuania does not own battle tanks, but it is now modernizing old tank ramps in training areas.

Perhaps more significantly, the country is building facilities near Vilnius with space for a battalion-sized NATO presence. Rožėnas told me the facilities will be completed in 2018 and will include dormitories, dining facilities, and sports facilities, the common setup for military accommodation. In addition, the ministry plans to build RSOM capabilities. RSOM (Reception, Staging, and Onward Movement) is essentially temporary accommodation for troops and storage for their equipment as they pass through a certain area.

With armed forces comprising 118,000 troops – the new government has announced plans to increase the figure to 150,000 -- Poland faces fewer challenges than its Baltic partners in providing facilities for NATO troops. But it, too, is conducting an ambitious military infrastructure construction program. The Ministry of Defense is planning to renovate Cold War-era military storage facilities and upgrade roads.

According to the Ministry, it spent PLN 172 million ($45 million) on NATO-related infrastructure projects last year and will spend PLN 212 million ($56 million) this year. Last year, a Ministry of Defense spokesman also announced that the government would also spend PLN 300 million ($79 million, about a fourth which contributed by the United States) to modernize and enlarge the Drawsko Training Area, Poland’s largest; it will be used by both Polish and NATO troops.

The question now is how well, and how quickly, the four countries can complete the construction. The tight schedule, with most construction to be completed within the next three years even as troops maintain their regular schedule at the sites, makes coordination particularly challenging. Nevertheless, to date all projects have been completed as planned.

But large gaps remain. Neither the Baltic states nor Poland have fully modernized their ports and railways. This is an area where NATO member states and the host countries can jointly finance construction. And although USACE involvement is positive, the host countries have to consider what proportion of the projects use local labor and materials, which recycles the investment into the wider economy. The danger of handing large parts over to the USACE is that Congress will pressure the USACE to employ US contractors.

The host countries and NATO also have to reassure Russia of the new infrastructure’s defensive nature. Regular public updates about the construction – similar to NATO’s updates about its exercises -- would increase trust in NATO presence among the public and limit unnecessary tensions with Russia. Realistically, however, even such efforts would be unlikely to persuade the Kremlin of NATO’s peaceful intentions.

Another question is what the troop presence will look like in the longer term. Rotational troops arriving without their families add less money to the local economy than long-term personnel accompanied by spouses and children. But their costs to the deploying country are lower as there are no schools, married quarters, or family support facilities to be maintained. And perhaps most importantly, local populations have to be brought onboard. Most local residents approve of rotational troops training in their area, especially if the foreigners are joined by domestic forces. Foreign troops training on their own, however, evoke completely different feelings altogether: the specter of occupying forces.