Ren'ai Jiao, which is located within 9°39'N to 9°48'N and 115°51'E to 115°54'E, is an atoll about 15 kilometers long and 5.6 kilometers wide. It has always been Chinese territory and is an integral part of China's Nansha Islands. As early as in the 2nd century BC, the Chinese people of the Western Han Dynasty (206BC-AD25) sailed in the South China Sea and discovered Nanhai Zhudao (South China Sea islands) in their long course of activities.
China was the first country to have named Ren'ai Jiao, and the first to have effectively exercised jurisdiction over it. The West calls Ren'ai Jiao "Second Thomas Shoal," believing that it was "discovered" by the British explorer Thomas Gilbert in the 1880s. But in fact, Chinese fishermen have been using it as an important fishing point from the wind before his discovery. 
In the navigation manual used by Chinese fishermen since the Ming Dynasty(1368-1644), Ren'ai Jiao is dubbed the Broken Sections. This name, which has lasted over a thousand years, implies that Ren'ai Jiao mostly exposed during low tide, with the southern half breaking into several segments.
China's sovereignty over the islands in South China Sea was not challenged until the 20th century. During the World War II, Japan invaded and illegally occupied several South China Sea islands. After World War II, the Chinese government resumed the exercise of sovereignty over these islands in accordance with the Cairo Declaration and the Potsdam Proclamation, and formally named Ren'ai Jiao as "Ren'ai Ansha." 
In 1948, China published the "Location map of the South China Sea Islands", which clearly incorporates the Nansha Islands in their entirety into China's map, and labels "Ren'ai Ansha" as part of the Nansha Islands. In 1983, China's Geographical Names Committee announced Ren'ai Jiao as its standard geographical name, noting that it's commonly used "Broken Sections" among local fishermen. In 1987, China's Nansha scientific research team conducted an all-round investigation of Nanhai Zhudao and landed on Ren'ai Jiao, leaving a stone monument and markers. The Law of the People's Republic of China on the Territorial Sea and the Contiguous Zone issued in 1992 also clearly stated that the Dongsha Islands, Xisha Islands, Zhongsha Islands, and Nansha Islands, including Ren'ai Jiao, are China's inherent territory.

Down-and-dirty plot
The Philippines was under Spanish, and later, US colonial rule. Yet as its suzerain, neither of the two countries included Ren'ai Jiao within its territorial boundaries, nor did they raise any objection to China's sovereignty over Nansha Qundao, which included Ren'ai Jiao. 
Prior to the 1970s, Philippine laws had clearly defined its territorial scope, which did not cover the islands and reefs in the South China Sea. However, since the 1970s, the Philippines has illegally occupied eight islands and reefs in China's Nansha Islands, namely, Mahuan Dao, Feixin Dao, Zhongye Dao, Nanyao Dao, Beizi Dao, Xiyue Dao, Shuanghuang Shazhou, and Siling Jiao. In June 1978, it unilaterally went beyond its territorial scope to set up the so-called "Kalayaan Island Group," which violates China's territorial sovereignty.
After the Meiji Jiao (also known as Meiji Reef) incident of 1995, the Philippines began to covet Ren'ai Jiao, which is not far from Meiji Jiao. 
"Back then, the Philippine military had an internal discussion and decided that since the Philippines had suffered a setback in Meiji Jiao, they would need to make up for it in some other ways. As a result, they played the trick of occupying an island by grounding their warship on it," Chen Xiangmiao, director of the World Navy Research Center at the National Institute for South China Sea Studies, told the Global Times.
On May 9, 1999, the day after the US bombed the Chinese Embassy in Yugoslavia, the Philippines dispatched BRP Sierra Madre, an old WWII-era warship, to invade Ren'ai Jiao and illegally left it grounded under the pretext of technical problems. In disregard of China's solemn representations, the Philippines brazenly claimed that it was an accident and that the warship could not be towed away due to "lack of spare parts."
In September 2003, upon the news that the Philippines was preparing to build facilities around that military vessel illegally grounded at Ren'ai Jiao, China lodged immediate representations. 

The then Philippine acting secretary of foreign affairs Franklin Ebdalin responded that the Philippines had no intention of constructing facilities on Ren'ai Jiao and that, as a signatory to the Declaration on the Conduct of Parties in the South China Sea (DOC), the Philippines had no desire to and would not be the first to violate the Declaration. However, this commitment was repeatedly broken by the Philippines.
In March 2014, the Philippine Department of Foreign Affairs issued a statement openly declaring that the vessel grounded at Ren'ai Jiao was placed there as a permanent Philippine government installation. This was an apparent attempt to provide an excuse for its continued refusal to fulfill its undertaking to tow away the vessel so as to illegally seize Ren'ai Jiao. China immediately responded that it was shocked by this statement and reiterated that it would never allow the Philippines to seize Ren'ai Jiao under any circumstances.
In July 2015, the Philippines stated publicly that the "maintenance repair" was being done to fortify the vessel.
Chen told the Global Times that after Philippine president Duterte took office in 2016, China and the Philippines reached an agreement on managing the dispute over Ren'ai Jiao. However, shortly after the current Philippine President Marcos took office, the Philippines did away with the agreement, leading to a sudden escalation of tensions over Ren'ai Jiao. 
At the same time, the current tensions in the South China Sea also stem from the meticulous planning by the US and Western countries. Over the last 20 years, biased press reports from Western media have depicted the Philippines as a "small impoverished country challenging the bullying of a superpower." 

For a long time, the US has been inciting the Philippines to repair and strengthen the illegally grounded warship. It has even sent military aircraft and warships to carry out so-called "free navigation" and "reconnaissance" operations, conducted military exercises and joint patrols in countries surrounding the South China Sea, and threatened China with the implementation of the US-Philippines Mutual Defense Treaty.
"The Philippines has always gambled regarding the South China Sea issue, attempting to commit infringements in the region during a time of great power competition. In the past, they secretly sent construction materials to Ren'ai Jiao. Now they go even further by developing a national strategy which seeks to occupy the so-called West Philippine Sea, with Ren'ai Jiao included," Hu Bo, director of the South China Sea Strategic Situation Probing Initiative (SCSPI), told the Global Times.
Through both words and actions, China can show its bottom lines to the Philippines, thus making it withdraw from the dispute. China's recent response concerning Ren'ai Jiao has already showed its determination to safeguard its sovereignty, Hu stressed.