The South Kara Sea basin does not announce itself from the surface. From the air, or from a ship, it looks like any other stretch of cold Arctic water — grey swells, distant ice, the occasional seabird. But the sedimentary rocks beneath the seabed continue the same structural story as the enormous oil and gas fields of western Siberia, which have produced hydrocarbons for decades. The East-Prinovozemelsky field is divided into three license blocks: EPNZ-1, EPNZ-2, and EPNZ-3, each holding billions of barrels of oil and trillions of cubic meters of natural gas. The field is classified as an undeveloped structure — meaning the reserves are estimated and the geology is understood, but the infrastructure to extract them has never been built.

In January 2011, Rosneft announced it would develop the East-Prinovozemelsky blocks in partnership with BP. The deal made headlines: a major Western energy company linking itself to Russia's state oil giant to crack open the Arctic frontier. But the arrangement fell apart in a dispute over ownership structures and the involvement of BP's existing Russian partners, the TNK-BP shareholders. By August 2011, Rosneft had found a new partner: ExxonMobil. The two companies committed $3.2 billion to a joint venture covering the three EPNZ blocks. Under the agreed terms, Rosneft would hold two-thirds of the venture; ExxonMobil the rest. Drilling preparations began. In 2014, the venture found oil — and then geopolitics intervened.

Russia's annexation of Crimea in 2014 triggered US sanctions that targeted precisely the kind of deep-water and Arctic energy cooperation that East-Prinovozemelsky represented. ExxonMobil was granted a brief exemption to safely complete a well it was already drilling, then it withdrew. The company later sought a full sanctions waiver from the US government to resume operations. In April 2017, the Trump administration denied it. The field's deadline for ExxonMobil to begin operations — set under the original agreement — ran until 2023, but without the partnership, development stalled. A deposit that geologists have measured in the tens of billions of barrels remains, as it has for decades, untouched beneath the Arctic sea.

The East-Prinovozemelsky field exists in a peculiar limbo. Its resources are not in doubt. The technology to extract them, while challenging, is not beyond reach. What remains unresolved is the question of which companies, under what political conditions, would be willing to invest in a project that requires sustained cooperation between Russia and the West — cooperation that, as of the mid-2020s, has collapsed. Arctic energy development also faces a new dimension of uncertainty: the same climate warming that is opening Arctic shipping lanes is forcing a recalculation of the economics and the environmental risks of drilling in newly accessible polar waters. The field waits. The ice above it recedes, a little more each year.