The prospect of offshore oil drilling also drove the quarrel between China, Japan and Taiwan over the Senkaku Islands off the eastern edge of China. Japan controls the islands, but as recently as last year the country expressed concern about a possible attack by China.
The same nations — along with Vietnam, Malaysia and the Philippines — contest control of the Spratly Islands in the South China Sea, another area rich in fish and gold.
Japan also is involved in squabbles with South Korea and Russia over a scattering of tiny islands. South Korea inhabits Tokdo and Takeshima islands, located between the two nations in the Sea of Japan, but Japan has contested the claim since the Russo-Japanese War of 1905. Russian gunboats still occasionally fire on Japanese fishermen near the Kurile Islands, which Russia took control of after World War II. Japan contests Russia's claim to four of the islands within the chain, and in 2001 the two countries agreed on the islands' governance without clarifying who owns them.
Other nations around the world battle over smaller pieces of land, though their disputes don't necessarily revolve around islands but more often feature oil.
"There are very few land boundaries in the world that are clearly defined," Pratt said.
Perhaps the most infamous regional dispute is over Kashmir, located between India and Pakistan. The nuclear-capable neighbors have struggled over the region since India gained its independence from Great Britain in 1947.
Not all such disputes deadlock in violence. Pratt's office offered assistance recently to the United Nations' International Court of Justice in its decision concerning the border between Nigeria and Cameroon. Both nations claim ownership of the Bakassi peninsula in the Gulf of Guinea, where there is potential for oil offshore, as well as several other smaller regions along their border. Peacefully, both countries brought their case before the court for third-party resolution.
"The International Court plays a very important role in significant conflicts" said Sean Murphy, a former legal adviser to the U.S. State Department who worked in the U.S. Embassy in The Hague. "It's mere presence is an achievement."
Murphy said the biggest obstacle facing the court — one that could prevent it from resolving Spain and Morocco's conflict — was getting both sides of the dispute to come before the court.
That doesn't mean all major nations spurn the court. In 1991, the United States and Canada accepted the International Court's resolution to their dispute over the maritime boundaries in the Gulf of Maine.
Talking It Out
More often, countries will seek third-party arbitration rather than through an institution like the United Nations.
In 1998, a group of neighboring countries, including the United States, helped Ecuador and Peru end their dispute over the border in the Cenepa Valley, which had led to bloodshed several times since the countries gained their independence from Spain in the 19th century.
Other disputes have been tougher to resolve. Venezuela still refuses to acknowledge an 1898 treaty that granted Guyana a 63,000-square-mile region called Essequibo, though reports from December said relations between the countries were on an upswing.