With warnings swirling over a possible war with Russia in a matter of years, NATO‘s European members have already started laying the groundwork for defenses, should Russian troops set foot on alliance soil.

“Russia is preparing for a war with the West,” Bruno Kahl, the head of Germany’s foreign intelligence service, said in late November.

But it’s not likely to be a large-scale attack into NATO territory, the intelligence chief warned. Moscow could opt for a limited incursion or upping its hybrid warfare tactics to probe the alliance’s conviction, Kahl said.

NATO is trying to prepare for both scenarios: an all-out war, and less obvious techniques designed to undermine stability in the alliance’s member countries.

“There are multiple options for Russia to test the cohesion of the alliance,” including limited land grabs, the former head of NATO’s Multinational Corps Northeast based in northwest Poland, Lieutenant General Jürgen-Joachim von Sandrart, told Newsweek just before leaving his post in November.

The urgency is now obvious from senior military and political officials. Andrius Kubilius, the European Union‘s commissioner for defense, said in September that defense ministers and NATO commanders “agree that [Russian President] Vladimir Putin could be ready for confrontation with NATO and the EU in six to eight years.”

Estonia’s foreign intelligence service warned in February NATO “could face a Soviet-style mass army in the next decade” if Russia successfully reforms its military. The army would be “technologically inferior” to NATO forces in areas other than electronic warfare and long-range strikes, the service said, but its “military potential would be significant.”

“If we take these assessments seriously, then that is the time for us to properly prepare, and it is a short one,” Kubilius, a former Lithuanian prime minister, told the Reuters news agency. “This means we have to take quick decisions, and ambitious decisions.”

The main catalyst is Russia’s full-scale invasion of Ukraine, prompting Sweden and Finland to abandon their long-held policies of non-alignment and join NATO, lengthening Russia’s border with the alliance.

Across Europe, NATO is now battling to raise defense spending up and beyond the two percent of GDP requested—but not enforced—by the alliance. Many countries have historically fallen far short of this benchmark in the decades since the end of the Cold War.

But times are changing. European nations have pledged to meet or exceed the target, and officials and experts broadly expect the incoming administration of President-elect Donald Trump to double down on pressure on Europe to increase military spending further.

The countries snaking along NATO’s eastern flank are way ahead. How quickly Europe will be able to pull up spending and prop up the companies producing more equipment, however, remains to be seen. NATO’s top military official, Admiral Rob Bauer, said in late last November that businesses “need to be prepared for a wartime scenario and adjust their production and distribution lines accordingly.”

“While it may be the military who wins battles, it’s the economies that win wars.” Bauer said.

Already, there are visible signs of preparations across Europe, particularly striking in the countries closest to Russia’s borders.

Serbian President Aleksandar Vučić said in July that NATO was “not ready now” for a possible war with Russia but that they “will be ready” in the future.

“They are already preparing for a conflict with the Russian Federation and are preparing much faster than some people would like to see, in every sense,” he told Serbian television, in remarks reported by Russian state media.

“We know this from military preparations. We know how they are being conducted. And I want to tell you, they are preparing for a military conflict,” Vučić said.

Germany has started putting together plans for how Berlin would would shield important buildings and installations in the event of an attack, and how Germany would be a conduit for hundreds of thousands of soldiers heading further east in Europe, the German daily newspaper, Frankfurter Allgemeine Zeitung, reported in November.

The first draft of the strategy paper, labeled “Operationsplan Deutschland,” is 1,000 pages long, the newspaper reported.

Baltic Defense Line

The three Baltic states of Latvia, Lithuania and Estonia signed an agreement back in January this year to beef up protection along their land borders with Russia and Belarus.

Belarus is a key Russian ally, and the Kremlin used Belarusian territory to launch the full-scale invasion of Ukraine in February 2022. The country also links Russia with its isolated Kaliningrad exclave, sandwiched between NATO members Poland and Lithuania.

“We are undertaking this effort so that the people of Estonia can feel safe, but if the slightest risk emerged, we would be ready for various developments more promptly,” said Estonia’s defense minister, Hanno Pevkur.

Tallinn said there would be a “network of bunkers, support points and distribution lines” along the border.

Lithuania’s defense ministry said in early September that it had “set up a blockade” on and near the bridge in Panemunė, the Lithuanian border settlement that connects the NATO country with Kaliningrad.

Vilnius said it had set up mines, and other defenses, like dragon’s teeth, against tanks and armored vehicles.

Dragon’s teeth are concrete blocks used to halt tank advances and prevent mechanized infantry from gaining territory. This type of anti-tank fortification has littered Ukraine.

“This is a precautionary step to ensure more effective defense,” Lithuania’s government said.

Lithuania’s neighbor to the north, Latvia, has put similar defenses in place. The Latvian government has said around €303 million ($318 million) will be funneled into building up defenses on its eastern border with Russia over five years. There will be outposts for support personnel, reinforced structures, anti-tank trenches and storage dumps for ammunition and mines, Riga said.

“We will be able to slow down and block the movement of potential aggressors more efficiently,” Latvian Defense Minister Andris Sprūds said in a statement in January.

In July, Riga said that obstacles designed to hamper military movements were now being “procured and transported to temporary storage areas near Latvia’s eastern border.” Russia lies to the east of Latvia.

Estonia’s ERR broadcaster reported in October that the Latvian military was testing barriers making up the Baltic Defense Line, including dragon’s teeth.

Kaspars Lazdinš, from the Latvian armed forces, said the military had used a T-55 tank to “simulate conditions similar to those our eastern neighbors might present.” The T-55 is a Soviet-era main battle tank.

“The anti-tank barriers held up well,” Lazdinš told the broadcaster, adding: “The concrete blocks successfully protected people and infrastructure from direct fire.”

Further to the south, staring down Kaliningrad and Belarus, Poland has started construction of what it has called its “East Shield,” costing over $2.5 billion and described by Warsaw as “the largest operation to strengthen Poland’s eastern border, Nato’s eastern flank, since 1945.”

Polish Prime Minister Donald Tusk visited the Polish border with Kaliningrad over the weekend to inspect fortifications being built on Warsaw’s territory.

“Poland’s investments have been a mix of building up both defensive capabilities and offensive capabilities, designed to deter Russia by convincing them that any attack would fail to achieve its objectives and come at very high cost,” said William Freer, a research fellow in national security at the U.K.-based think tank, the Council on Geostrategy.

“Poland’s ‘East Shield’ fortifications build on the lessons of the fighting in Ukraine, which have shown how hard it is to push through heavily entrenched defenders,” Freer told Newsweek. “In combination with traditional fortifications such as dragon’s teeth, East Shield will make use of a suite of electronic warfare and surveillance systems.”

Mass Evacuation Plans

The preparations aren’t just military, they’re civil, too. In mid-November, NATO’s newest member, Sweden, published a brochure it said helped the country’s residents to “learn how to prepare for, and act, in case of crisis or war.” The pamphlet outlines what a heightened state of alert would mean, how each inhabitant would pitch in to a war-time effort, and what different sirens sound like.

“Military threat levels are increasing,” the leaflet warns the Scandinavian country’s citizens. “We must be prepared for the worst-case scenario—an armed attack on Sweden.”

Norway, too, has published a leaflet on how to deal with “extreme weather, pandemics, accidents, sabotage—and in the worst case acts of war.”

Finland has publicly-available guides on how it prepares for “the worst possible threat, war.”

In the Baltics, Agnė Bilotaitė, Lithuania’s interior minister, said in September that each of the country’s local authorities had to quickly draw up evacuation plans that are “ready” to be put in motion.

“It is important to note that we are at the forefront, so today, civil defense has become a priority on our agenda,” Bilotaitė said. The Lithuanian minister has urged neighbouring countries to do the same.

Latvian Interior Minister Rihards Kozlovskis said in September that the Baltic state had roughly 5,000 underground buildings that Riga hoped to have “ready for use as shelters by November.”

Bilotaitė said in October that Vilnius would spend €12 billion in 2025 to install and upgrade shelters.

“If necessary, we could shelter two cities like Vilnius underground,” Vilnius Mayor Valdas Benkunskas said in remarks reported by domestic media.

Germany’s government has also said it is putting together a list of bomb shelters that will be available for citizens to see where their closest shelter is.

Air Defenses

In January, the Baltic states also stressed the need they felt to build up NATO air defenses on the eastern flank, according to a Latvian government readout.

Hungary’s defense minister, Kristof Szalay-Bobrovniczky, said in November that Budapest will place an air defense system in the northeastern region of the country.

“We still trust that there will be peace as soon as possible, through diplomacy instead of a military solution,” Szalay-Bobrovniczky said in a video address. “However, to prepare for all possibilities, I ordered the recently purchased air control and air defense systems and the capabilities built on them to be installed in the northeast.”

Europe has a chronic shortage of air defenses, although military and political officials have swerved providing specifics.

East Versus West

While Poland, the Baltic states, Finland and Sweden, as well as Romania, which borders western Ukraine, have significantly upped defense investment, western Europe is lagging behind.

“It is no coincidence that the greatest increases in defense spending in NATO are coming from those closest to Russia,” Freer said. “Behind NATO’s eastern flank, other allies are acting with less urgency and have proven far less willing to increase investment at the same level.”

Admiral Sir Tony Radakin, the head of the British armed forces, conceded in November that the U.K. was in a “slightly weaker” position than many countries closer to Russian soil.

“We don’t have some of the civil aspects or planning aspects that other countries within NATO have as part of their traditions,” Radakin said.

The U.K. has committed to increasing defense spending to 2.5 percent of GDP. France is on course to hit the NATO target of 2 percent this year, as is Germany.

Estonia’s defense spending is hovering at around 3.4 percent of its GDP, with plans to hike this to 3.7 percent by 2026. Lithuania said in March it would raise defense spending to 3 percent from 2025, and its defense minister has floated hitting 4 percent, to finance new long-range air defenses and other equipment. Poland has said it will spend 5 percent of its GDP on the military in 2025.

Western European countries are taking “some meaningful steps,” Freer added. Countries in the alliance are looking at how to improve NATO’s integrated air and missile defense capabilities, pulling lessons from Russia’s hammering of Ukraine.