In 2007, two Russian submarines plunged down 2.5 miles (4 kilometers) into the Arctic Ocean and planted a national flag onto a piece of continental shelf known as the Lomonosov Ridge. Rising from the center of the Arctic Basin, the flag sent a clear message to the surrounding nations: Russia had just laid claim to the vast oil and gas reserves contained in this underwater turf.

Russia’s dramatic show of power had no legal weight — but it isn’t the only nation that’s trying to stake claims to the Arctic’s vast depository of oil and gas. The United States, Norway, Sweden, Finland and China are all trying to cash in. It’s no wonder: Projections show that the area of land and sea that falls within the Arctic Circle is…