First the dotted line on Chinese maps lost two of its hyphens in 1952, when, in a moment of socialist bonhomie with Vietnam, Chairman Mao Zedong abandoned Chinese claims to the Gulf of Tonkin. Then, on July 12, 2016, an international tribunal ruled that the now nine-dash demarcation could not be used by Beijing to make historic claims to the South China Sea, parts of which are claimed by six governments. The line, first inscribed on a Chinese map in 1947, had “no legal basis” for maritime claims, deemed the Permanent Court of Arbitration in the Hague. Beijing reacted with outrage to the judgment, which delegitimized China’s maritime ambitions according to international law.

On July 18, China’s naval chief Wu Shengli told the visiting U.S. chief of naval operations that Beijing would not halt its controversial campaign to turn the contested South China Sea reefs it controls into artificial islands complete with military-ready airstrips. China “will never give up halfway” on its island-building efforts, said Wu, according to Chinese state media. Also on Monday, the Chinese air force announced that it had sent bombers on “normal battle patrols” over Scarborough Shoal, a disputed reef that Beijing effectively seized from Manila in 2012. Analysts worry that China could next build on Scarborough Shoal, placing a militarized Chinese island off the Philippine coast. Far from hewing to the international court’s July 12 judgement on the nine-dash line, and contested features within that boundary, Beijing has made clear it considers the award null and void.

Wang Ying, a Chinese marine geographer, also feels aggrieved by the tribunal’s award. “They didn’t respect history,” she says, of the international court. “I totally agree with the response of our government.” The 81-year-old member of the prestigious Chinese Academy of Sciences is the disciple of Yang Huairen, a Chinese geographer who, in 1947, helped etch the U-shaped, 11-dash line on Chinese maps to demarcate roughly 90% of the contested South China Sea for his homeland. “All the lines have a scientific basis,” says Wang, who still teaches at Nanjing University in eastern China. “I’m a scientist, not someone in politics.”

Although the phrase nine-dash line is used commonly outside of China — to the point where an international arbitration court was asked by the Philippines to adjudicate on its legality — the words rarely appear in official Chinese media. Research by David Bandurski of the China Media Project in Hong Kong found that through July 12, the phrase was only used in six articles in the People’s Daily, the mouthpiece of the ruling Chinese Communist Party. After the tribunal’s judgment was made, state media began a campaign to defend China’s maritime claims, encapsulated by the phrase “not one [dash] less.”

Wang says the line is broken up because it’s a maritime boundary. “It’s not like a fixed borderline on land,” she explains. “As a scientist, I’d say it’s impossible to have a fixed border on the sea … the waves in the ocean move.” Wang also contends that the dotted line is a “very clear” divide between the deep ocean that is China’s domain and a Southeast Asia that doesn’t have much in the way of a continental shelf. (Southeast Asian nations like Vietnam, which has a long continental shelf, would disagree.) “When we made the line, we stressed a humanitarian spirit,” Wang says. “We allow the neighboring countries to pass through it without obstacles.” (In fact, international maritime law allows for such transit.)

DigitalGlobe overview imagery comparing Fiery Cross Reef from May 31, 2014, to June 3, 2016. Fiery Cross is located in the western part of the Spratly Islands group. DigitalGlobe/Getty Images

Humanitarian spirit was not shown to Yang, Wang’s mentor. Born in 1917 and educated in Britain, Yang was employed by the Nationalist government of China. As politicians looked to strengthen a nation emerging from war and privation, Yang began cataloguing what the Kuomintang government claimed were China’s maritime treasures. In 1947, he worked on the map introducing the 11-dash line and 286 bits of rock and turf in the South China Sea. Yang helped to officially name each chunk of rock and reef, referring to the territory collectively as the “South China Sea Islands.” But two years later, the Nationalists lost to the communists in China’s civil war. During the Cultural Revolution, Yang was persecuted as an “antirevolutionary academic authority” because of his association with the defeated nationalists. “He never talked about the line he made in the South China Sea again,” says Wang of her academic guide’s latter years. “He was treated badly.” (Yang died in 2009.)

Wang nurtures other historic grievances. Chairman Mao’s decision, through Premier Zhou Enlai, to hand over the Gulf of Tonkin to Vietnam in 1952, thereby removing two of the 11 South China Sea dashes, still rankles. “It was stupid,” she says. “Mao Zedong should not have given it up.” By contrast, she contends, Mao went to war with India over a border tiff. Why the difference? “China was a continental kingdom not a maritime one,” she says. “Historically, we did not pay much attention to the oceans.” Indeed, after a burst of seafaring exploration during the Ming dynasty (1368-1644), China’s emperors largely shut their empire off from the seas. As a consequence, Wang says, cartographic proof of China’s claims to the South China Sea is scarce. “We had no good maps during the Qing dynasty,” she says of the imperial age that replaced the Ming and ended in 1911. “The Qing just showed the South China Sea as a small lake.”

Still, like other Chinese scholars, Wang contends that plenty of historical evidence supports Beijing’s claims of ancient sovereignty over the South China Sea — from pottery shards to navigational handbooks used by Chinese fishermen. Of course, other nations that share the waterway, such as Vietnam, Malaysia and the Philippines, have their own archeological finds that they say prove their peoples also roamed the South China Sea. Besides, international maritime convention, to which China is party, pays less heed to history when it comes to deciding claims to the sea by nonarchipelagic nations.

For decades, Chinese schoolchildren have been taught that their homeland’s furthest southern reach was the underwater James Shoal (known in Chinese as Zengmu, a transliteration of “James”), which is located around 50 miles off the coast of Malaysia. Waters around the shoal are home to Malaysian oil and gas platforms. This geography lesson notwithstanding, Chinese maps gave scant attention to the South China Sea. That began to change after 2009, when a map with the nine-dash line was attached in a submission to the U.N. during a dispute with Vietnam. Today, Chinese passports are emblazoned with a map with nine dashes through the South China Sea—plus a 10th that ensures Taiwan, to which the Nationalists retreated in 1949, is counted as Chinese territory.

Curiously, though, the dashes on the 2009 map (and on current Chinese passports) are located in slightly different places from those on the original 1947 map. In several cases, the new dashes hug the coasts of other Southeast Asian nations more closely, giving China an even more expansive claim to the waterway “Because the people who made the [newer] map were not strict, they didn’t follow the right image scale,” says geographer Wang. “Some people are not working that rigorously.” And though China also makes territorial claims in the East and Yellow Seas, these specks of land are not marked by dotted boundaries. Dashes, it appears, are reserved for the South China Sea.

Missile destroyer Guangzhou launches an air-defense missile during a military exercise in the water area near south China's Hainan Island and Xisha islands on July 8, 2016 Xinhua News Agency—Xinhua News Agency/Getty Images

Ultimately, it’s not even clear what the nine-dash line means to China. Is it all water within the boundary or all territorial features? For the average Chinese, every drop of sea within the dashes is clearly China’s. “The discontinuous line,” says Wang, “means the national border on the sea.” The geographer clarifies further. “The dash lines mean the ocean, islands and reefs all belong to China and that China has sovereign rights,” she says. “But it’s discontinuous, meaning that other countries can pass through the lines freely.”

Certainly, some of China’s actions seem to support that definition of the line. In 2012, a fleet of Chinese maritime surveillance cutters patrolled the South China Sea in what was dubbed a “regular rights defense patrol.” A Chinese state TV crew was brought along for part of the ride. Andrew Chubb, a Ph.D. student at University of Western Australia who studies Chinese policy on the South China Sea, noted in his research that the route that Chinese ships took, which was documented on state TV, echoed the nine-dash line. Chinese audiences would be left with the natural impression that the dotted demarcation was the extent of Chinese sovereignty. In addition, as recently as 2012, Chinese boats cut seismic cables used for energy exploration by Vietnam. The cable-cutting occurred near the western extent of the nine-dash line, again suggesting that these waters were China’s.

But international maritime law, which was formed after China’s dotted line was created, doesn’t see it that way. Even if China controlled every contested Spratly rock and reef — currently Beijing holds a minority of all Spratly features, which they have built into artificial islands — the law of the sea would not give China rights to all waters within the nine-dash line. Back in 2014, Wu Shichun, the influential head of the Chinese government-funded National Institute for South China Sea Studies, told TIME that the nine-dash line did not represent a blanket claim to all maritime space. “China has never claimed all waters in the U-shaped line,” he said. “From the historical archives from Taiwan and China, it’s clear that the line shows ownership of insular features within the U-shaped line.” A government statement reacting to the July 12 award may hint that official policy agrees that the line denotes all territory within the dotted demarcation, not all waters. Either way, the fact that ambiguity remains at all proves the complicated legacy of the nine-dash line.

Meanwhile, tensions remain in the wake of the July 12 ruling. The Philippines, which lodged the case against China with the international tribunal in 2013, had said it would dispatch a former President to Beijing to negotiate on South China Sea issues. But on Tuesday Philippine Foreign Minister Perfecto Yasay told local broadcaster ABS-CBN that Beijing’s wish not to discuss the international tribunal’s judgment made bilateral talks tough. A day earlier, Beijing announced another set of military drills in the South China Sea, following live-fire action earlier in the month. China is cordoning off part of the South China Sea for war games from July 19 to 21. Entrance to these waters by foreign ships, China’s Maritime Safety Administration said, will be “prohibited.”

— With reporting by Yang Siqi / Beijing

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