London — ARCHAEOLOGY has long been exploited as a political tool. Hitler used artifacts and symbols to manufacture a narrative of Aryan racial superiority. The Islamic State proves its zealotry by destroying evidence of ancient history. Underwater archaeology — the world of shipwrecks and sunken cities — has mostly avoided these kinds of machinations, though. Since no one lives beneath the sea, leaders haven’t found many opportunities for political gains from archaeological sites there.

That is, until now.

In the past few years, politicians in Canada, Russia and China have realized that they can use shipwrecks on the sea floor to project their sovereignty into new maritime territories. And this politicized abuse of science is putting the world on a path toward conflict.

For decades, global powers have been engaged in a race to exploit lucrative marine resources, from oil to fisheries to control of strategic waterways. But they have faced a challenge: How can a country claim new territory despite the restrictions of the United Nations Convention on the Law of the Sea? It turns out that “historical ties” to resource-rich regions can conveniently help to contravene international law.

Last year, Canada announced the discovery of H.M.S. Erebus, Sir John Franklin’s flagship, which disappeared during a Northwest Passage expedition in 1845. Stephen Harper, then the prime minister, personally announced the discovery. His government and its allies provided significant funding for the research. But Mr. Harper isn’t just a history buff; his interests are practical.