The world's land areas have been well studied and documented. By now it seems like national borders would be clearly marked and settled. However, there are a surprising number of borders that countries disagree and fight over. Such contested borders can cause a great deal of trouble.

Fighting—and Sometimes not Resolving—Wars

The most obvious effect of contested borders is conflict. Disputes can range from political tension to war. Eastern Europe is one region where a period of rapid change has led to struggles over borders. Many countries there were once under the control of the Soviet Union (U.S.S.R.). When the Soviet Union broke up around 1990, many new borders had to be drawn. Some countries went to war over their new nations' boundaries. Others have faced aggression from Russia, once the most powerful part of the Soviet Union. For example, Russians invaded and seized control of Crimea in 2014. Crimea is considered a region of Ukraine. But it has many residents who consider themselves Russian. They voted to break away from Ukraine and join Russia. However, the vote's fairness has been questioned by Ukraine and some other nations. Meanwhile, the borders of Ukraine and Russia remain in question.

Some border disputes are the result of past wars. Countries have refused to sign peace treaties because they claimed the same land. For example, the Soviet Union invaded the Japanese-held Kuril Islands during World War II (1939-1945). Agreements at the war's end gave all of the islands to the Soviets. Seventy-five years later, though, Japan still claims the southernmost islands. The Japanese government has never signed a treaty officially ending its war with Russia because of it. Another high-profile example is North Korea and South Korea, which fought in the Korean War (1950-1953). In 1958, the two countries finally signed an agreement to end the fighting between them. No peace treaty was signed, though. Ever since there has been a demilitarized zone between the two countries. Only in 2018 did the two sides agree to formally end the war. However, military tension and the contested border remains.

Sharing, or Fighting for, Significant Sites

Contested borders are often found near sites that are important to two or more nations. The Israeli/Palestinian conflict in the Middle East is a familiar example. Israel was created after World War II. It took form on lands where many Palestinians lived. Israel's major cities contain sites that are holy for Jews, Christians, and Muslims. Their historical and religious claims are why Jewish people wanted their own country there. It also explains why Palestinian Muslims did not want to give up their claims. Israeli forces also occupy Gaza and the West Bank. These are two main territories where Palestinians live. They are sources of the ongoing conflict.

Economic Concerns

Economics also plays a role in contested borders. Areas with valuable resources are often the cause of these disputes. One such area is the Spratly Islands. It is a group of small islands in the South China Sea. Six different countries lay claim to them: Vietnam, Malaysia, Brunei, the Philippines, China, and Taiwan. The dispute is the result of decades of rivalry and changing maps. However, competition rose after oil and natural gas reserves were found in the seabed there. These resources may be worth trillions of dollars. Such wealth motivates the countries to push for their territorial rights.

Trouble with Maps

Modern technology makes it possible to make very accurate maps. Still, mapmakers face criticism when drawing contested borders. They may be accused of choosing sides. In 2014, for example, Google Maps—an online map service—showed Crimea differently depending on where the user lived. Users in the United States and Ukraine saw a dotted line. It indicated a contested border. In Russia, though, viewers saw a solid black line. It indicated Crimea was now part of Russia.

Such details may seem unimportant. In world affairs, though, they send a message. Drawing borders is more than a question of geography. They have a symbolic meaning. Countries and people may use them to promote or defend their cause.