HOHENFELS, Germany (AP) — On a moonless and rainy night, a group of soldiers emerged from a ramshackle building meant to resemble a church. The alpine terrain loomed over them as they quietly set off for the tree line of the German countryside a short distance away.

The soldiers are members of the Polish special forces and are taking part in an exercise designed only months ago that simulates moving through enemy lines, traversing miles of enemy territory and launching a drone strike on a key enemy location.

Initially designed by the Army’s Green Berets for U.S. special forces, the exercise that began Friday is informed by and simulates many of the challenges that Ukrainian troops have experienced in their conflict with Russia. It is the first time a NATO ally like Poland has undertaken the training, and it comes at a time when tensions between Russian President Vladimir Putin and NATO countries have escalated.

“We’re using lessons learned from Ukraine,” an Army Green Beret officer assigned to the training complex said Thursday. “All of those effects that we’re seeing either Russia or Ukraine having to overcome — we’re doing our best to replicate.”

The Associated Press received rare access to both the training ground and the troops conducting the exercise, which has only been conducted twice before, both times this year, by two different Green Beret teams.

The drill highlights the focus that some parts of the U.S. military have on learning the latest techniques in drone warfare, pioneered by Ukraine during its 4 1/2-year effort to repel Russian forces. It also shows how the U.S., its NATO allies and Ukraine are working together to counter the threat of possible further Russian action in coming years even as the Trump administration has warned of troop drawdowns in Europe.

CIA Director John Ratcliffe went to Moscow this week to warn Russia not to attack NATO countries, The Wall Street Journal reported. Russia has the appetite to conduct sabotage and cyberattacks against NATO countries, but Putin wants to avoid a direct confrontation, according to three Western officials, who spoke Friday on condition of anonymity to discuss sensitive military matters.

How special forces are learning to sneak behind enemy lines to deploy drones
During the exercise in Germany, a senior enlisted soldier familiar with the training scenario at Joint Multinational Readiness Center Hohenfels — about an hour’s drive southeast from Nuremberg — said the plan is to run it several times a year. The officer said he expects most, if not all, of the 32 NATO nations to express interest in sending their troops to try the exercise.

Both spoke on condition of anonymity in line with the U.S. military’s longstanding policy of not publicly identifying individual members of special forces units.

Poland’s special forces will be expected to sneak past a U.S. Army airborne infantry unit, whose soldiers will play the enemy. The U.S. airborne infantry unit will parachute into the closed-off training area at the Army’s Hohenfels base and set themselves up into a front line.

Assuming the Polish forces can make their way past the U.S. Army, they must then move north — through about 60 miles (100 kilometers) of German countryside — to another training area in the town of Grafenwoehr, where they are expected to destroy a simulated target.

In between lie German farms and villages, private and government cameras, as well as a city with a large population, all of which not only pose as obstacles but also create the potential for them to be spotted.

The senior enlisted soldier said that in previous instances of the exercise, the Army Green Berets removed their uniforms “so they can blend in” before adding that “blend in also means don’t get seen by civilians.”

German civilians in the area largely are not aware of the exercise and serve as a reasonable test of how well special forces can blend into the local population. If they fail, reports of suspicious people to police will make it back to the military, which will use them to pinpoint the team.

“This is supposed to be Russia and you’re going to stand out in Russia,” the enlisted soldier added.

Plus, the U.S. Army also will be looking for the Polish forces with drones of their own.

If they’re spotted, “now you have the entire Russian arsenal coming at you,” the enlisted soldier said.

The U.S. Army can either send a military police unit to hunt for the Polish special forces with dogs or direct more drones to the area. In previous versions of the exercise, the U.S. Army had access to more than a hundred drones, the enlisted soldier said.

Troops are able to be “captured or killed” as part of the training.

Countries seek help from Ukraine on drone warfare
While the exercise taps into drones and NATO teamwork, the message of collaboration and the value of drones has been somewhat mixed lately across the military.

President Donald Trump stirred confusion among NATO allies by going back and forth on drawing down U.S. troop levels in Europe, and the administration has launched a force review on next steps. And last week, the Army’s top officer shuttered a unit that specialized in drone warfare.

But overall, there is growing interest in tapping Ukraine for its expertise on modern warfare and, specifically, drones.

In March, Ukrainian President Volodymyr Zelenskyy said his country was helping five countries in the Middle East and Gulf region counter Iranian drone attacks launched during the war with the United States, while the U.S. and European countries were among those requesting support.

Meanwhile, the number of mysterious drone incursions in Europe have grown, including as recently as this month, when a pair of drones were spotted over a German military base and a drone carrying explosives was found at a key cargo airport in Germany.