The U.S. Navy recently announced it had stood up a 150-bed field hospital in one of the most unusual places—a cave in an undisclosed location in Norway. The hospital is just the latest of Pentagon deployments to cave systems in Norway, including U.S. Marine Corps combat equipment and even nuclear-powered attack submarines.

While the cave deployments are important to help defend Norway from its bigger Russian neighbor, it also provides a secure base for operating in the increasingly open Arctic region. Norway is in one of the most strategically important regions in the Arctic.

The oil-rich NATO member shares a border with Russia and sits astride the Norwegian Sea, which the Russian Northern Fleet must pass through to enter the North Atlantic. But as rich as Norway is, it is heavily outnumbered in the region by the Russian military.

NATO military allies, particularly the U.S. Marine Corps, regularly practice reinforcing the country in the event of war, stymying a Russian invasion. Norway is in one of the most strategically important regions in the Arctic. The oil-rich NATO member shares a border with Russia and sits astride the Norwegian Sea, which the Russian Northern Fleet must pass through to enter the North Atlantic.

But as rich as Norway is, it is heavily outnumbered in the region by the Russian military. NATO military allies, particularly the U.S. Marine Corps, regularly practice reinforcing the country in the event of war, stymying a Russian invasion. READ MORE