Tensions between Manila and Beijing in the South China Sea — a key shipping route that sees trillions of dollars worth of global trade transiting each year — have recently increased.

The Second Thomas Shoal, also known as the Ayungin Shoal, is a disputed area in the South China Sea, controlled by the Philippines military but claimed as its own by China.

In April, a Chinese coast guard vessel nearly collided with a Philippines fishing boat in disputed waters, as it attempted to block a Philippine patrol vessel in the South China Sea. This occurred a day after Philippine President Ferdinand Marcos Jr met Chinese Foreign Minister Qin Gang in Manila.

The Philippines coast guard accused China of "aggressive tactics" after the incident.

In February, just one month after President Marcos Jr visited his Chinese counterpart Xi Jinping in Beijing, the Philippine Coast Guard had complained that the China Coast Guard had twice shone a military-grade laser at its ship, causing temporary blindness to the crew. Marcos later summoned the Chinese ambassador to the Philippines, Huang Xilian.

Fishing rights in the South China Sea

"The Philippines wants to enjoy its fishing rights within its [Exclusive Economic Zone, EEZ], which China has denied since it began the occupation and militarization of some areas in the [South China Sea]. Before China started with its more aggressive actions, fishermen from many countries in the region could fish these areas freely," Dr. Elaine Tolentino, an international relations analyst said.

"The Philippines hopes that we could talk about fishing rights in the South China Sea and ensure the security of the country's maritime territory," she added.

The EEZ, an area where sovereign states have jurisdiction over natural resources, was adopted under the UN Convention on the Sea in 1982.

Countries such as Indonesia, Malaysia and Vietnam have also complained of Chinese vessels encroaching its waters in recent years.

Hague ruling favors the Philippines

In 2016, an international tribunal in The Hague ruled overwhelmingly in favor of the Philippines in its long-running maritime dispute with China over claims of ownership of areas of the South China Sea. Beijing asserts that the territory within its so-called nine-dash line is its own, despite this being declared by The Hague as unlawful under international law. China rejects the ruling, which also found that Beijing's recent land reclamation activities, and other activities in Philippine waters, were illegal.

Last week, President Marcos said that Beijing had agreed to "sit down" and discuss fishing rights. He reiterated that a "direct communication line" should be established and that the overall priority was to safeguard Philippine maritime security. He said that he had asked the Philippines Coast Guard and Department of Foreign Affairs to put together a map of fishing grounds to present to Beijing.

But Jay Batongbacal, a maritime law professor at the University of the Philippines, is skeptical. "Even suggestions of new communications channels are pointless; the Philippines and China announced the establishment of a 'hotline' between coast guards in 2017, but it did nothing to change China's aggressive behavior."

He said that China had been "actively interfering with fishing activities" in the South China Sea since 2012. "It started as a result of it taking control of the Scarborough Shoal, approximately 124 nautical miles from Luzon, and eventually spread south to the Spratly Island region and the Philippine [Exclusive Economic Zone]. Since 2013, Chinese fishing vessels and maritime militia have been deployed in massive numbers to fish and anchor in the principal coral reefs and fishing grounds of Philippine fishers."

Furthermore, he added, though there were ongoing talks between Beijing and Manila, "to date, nothing has come of it."

Strengthened ties with US

Since taking office last year, President Marcos has strengthened ties with the US after a difficult period of strained bilateral relations under his predecessor Rodrigo Duterte. Batongbacal explained that this meant that the Philippines' stance towards China was more robust now.

He said that China's "incursions and coercion" were what had driven the government to "to re-energize and deepen defense and security relations with the US and the West."

"The current administration has stated its continuing openness to talk. Despite this, China has only tightened its grip even more on the Philippines' waters and acted more and more aggressively. It is up to China now to demonstrate sincerity and action that builds trust and confidence," he concluded.

"Beijing will likely reassert its 'indisputable sovereignty' over its claims in the West Philippine Sea and urge Manila not to complicate the relationship by focusing on maritime disputes or expanding its security relationship with the United States," forecast Raymond M. Powell from the Gordian Knot Center for National Security Innovation at Stanford University. "China will stress the need to resolve all disputes bilaterally, and not to 'involve outsiders' — especially the US."

Powell, who is a retired colonel in the US Air Force, also said that Beijing would likely "warn the Philippines" against taking further "'provocative' actions, such as attempting to enter the Second Thomas Shoal or publicizing the activities of China's security vessels."

"China may level implicit threats by suggesting that any further 'unwise' actions by the Philippines could lead to difficulties in the economic relationship between the two countries," he added.

One of world's biggest flashpoints

The South China Sea has become one of the world's biggest flashpoints as tensions between Washington and Beijing have increased, not least over Taiwan.

At the end of April, the US urged Beijing to stop harassing Philippine vessels after Manila and Washington conducted their largest-ever joint military drills in the waters across the South China Sea.

Officials said that the Balikatan war games, which lasted for two weeks and involved over 17,000 troops, 12,000 of whom came from the US, were conducted to strengthen international alliances and improve each military's ability to respond to emergencies in the Indo-Pacific. The exercises saw the troops simulate the defense of a small Philippine island and sink a mock enemy warship.

Edited by: Anne Thomas