In preparation for a looming fight with Russia, for the first time the Corps temporarily moved some of its M1A1 Abrams tanks holed up in secret caves in Norway to Finland.

It was for a large-scale annual training exercise featuring mechanized units known as Arrow 18, and it was the first time the Corps and its Abrams tanks have ever participated in the evolution, which took place from May 7-18.

The exercise involved only 30 Marines with nearly 5,000 Finnish soldiers, roughly 150 armored vehicles and 300 other military vehicles — a substantial display of firepower and deterrence flaunted not far from the Russian border.

But the Corps pulled out all the stops by moving its main battle tank from a series of secret cave complexes in Norway — a Cold War era storage program designed to rapidly equip Marines for a fight with Russia — to Pojankangas Training Area near Kankaanpaa, Finland for the exercise.

Exercise Arrow is an annual Finnish multinational exercise, and this was the first time that U.S. Marines “participated in the exercise with the purpose of exercising mechanized infantry, artillery, and mortar field training skills in order to increase interoperability, reassure partner nations, improve readiness and reinforce relationships,” Marine spokesman Lt. Brett Lazaroff said in an email to Marine Corps Times Tuesday.

The Corps’ Abrams have been stored in a series of sprawling cave complexes in Norway known as the Marine Corps Prepositioning Program-Norway, which houses thousands of Marine Corps armored vehicles, artillery and other equipment.

The Assistant Commandant of the Marine Corps Gen. Glenn M. Walters visits U.S. Marines and Norwegian Military members deployed in conjunction with the Marine Corps Prepositioning Program, Vaernes, Norway, April 24. (Cpl. Hailey D. Clay/Marine Corps)
The Assistant Commandant of the Marine Corps Gen. Glenn M. Walters visits U.S. Marines and Norwegian Military members deployed in conjunction with the Marine Corps Prepositioning Program, Vaernes, Norway, April 24. (Cpl. Hailey D. Clay/Marine Corps)

The Corps has been storing equipment in this network of caves since the 1990s in preparation for a potential heavyweight bout with Russia.

The caves hold at least enough equipment to support a Marine Air-Ground Task Force.

Corps officials say it is relatively routine to move vehicles and other equipment from the caves to various training ranges in Europe.

But Arrow 18 is the first time the Corps and its Abrams have participated in an exercise in Finland.

Finland is a key strategic partner to the U.S., especially as it seeks to deter Russian aggression in the region. And the country boasts an extensive border with Russia.

Currently, Finland is a nonaligned country with NATO. But the country has been seeking closer defense ties with the U.S. ever since Russia’s invasion of Ukraine in 2014.

In early May, Finland and Sweden, another nonaligned country, signed a letter pledging increased national security cooperation between the nations.

The nonbinding letter was signed by U.S. Secretary of Defense Jim Mattis, Swedish Minister of Defence Peter Hultqvist and Finnish Minister of Defence Jussi Niinistö.

The two defense ministers said the signed letter would bring emphasis on joint training exercises.

“Proven partnerships are built upon shared values, experiences, and vision; participating in exercises like this allow us to help build on this proven partnership,” Lazaroff said.

While the Abrams tanks came from caves in Norway, the Marines participating in Arrow 18 hailed from Washington state with 4th Tanks, Company B. The Army’s 2nd Cavalry Regiment and a Norwegian intelligence platoon also were in attendance at the exercise.