Iceland is a founding member of NATO but doesn't have its own army, or even a defense budget.

During the Cold War, Iceland was crucial in the alliance's efforts to detect Soviet submarines using P-3 Orion patrol aircraft because the island lies at a chokepoint known as the Greenland-Iceland-UK (GIUK) gap between the Arctic Ocean and the Atlantic.

That strategic location was and still is especially important to the US which is why among security experts, Iceland is often dubbed an "unsinkable US aircraft carrier" in the middle of the North Atlantic.

But US President Donald Trump threatening Greenland and the NATO alliance as a whole, as well as growing tensions in the Arctic have Iceland on edge.