This promises to be a landmark year for the claimant countries and other interested parties in the South China Sea disputes. Developments that have been underway for several years, especially China’s island-building campaign in the Spratlys and Manila’s arbitration case against Beijing, will come to fruition. These and other developments will draw outside players, including the United States, Japan, Australia, and India, into greater involvement. Meanwhile a significant increase in Chinese forces and capabilities will lead to more frequent run-ins with its neighbors.

Alongside these developments, important political transitions will take place around the region and further afield, especially the Philippine presidential elections in May. But no matter who emerges as Manila’s next leader, his or her ability to substantially alter course on the South China Sea will be highly constrained by the emergence of the issue as a cause célèbre among many Filipinos who view Beijing with wariness bordering on outright fear. The same dynamics are at play in Vietnam, where the course of South China Sea policy is not expected to change following last month’s Communist Party congress despite the re-election of Nguyen Phu Trong, who is generally seen as more pro-Beijing, as party chief.

The Philippines argued the merits of its case against China’s claims in the South China Sea before an arbitral tribunal at the Permanent Court of Arbitration in The Hague in November 2015. Afterward the five judges asked the Philippine legal team for written answers to a final round of follow-up questions. They are now expected to enter deliberations and issue a ruling around late May. That decision will be final and legally binding on both parties, despite Beijing’s refusal to take part in the proceedings or recognize the tribunal’s jurisdiction.

The case is complicated—it consists of 15 separate claims—and so the final shape of an award from the tribunal is unknown. However, the judges will almost certainly rule that China’s nine-dash line is not a valid maritime claim and that China is not entitled to any historic rights beyond the regime of territorial seas, exclusive economic zones, and continental shelves laid out in the United Nations Convention on the Law of the Sea (UNCLOS). This will not affect China’s territorial claims to the disputed islands and rocks of the South China Sea, nor will it necessarily mean that Beijing cannot make large claims to the seabed and waters in the area. But it will amount to an order that China clarify its maritime claims based on entitlements from land features, not ambiguous dashes on a map.

Beijing will not suddenly clarify its claims in the South China Sea because the tribunal orders it to do so. The Chinese government has repeatedly said that it will not recognize any ruling. But it has also worked hard since Manila brought the case in early 2013 to get the Philippine government to drop it. That is because being branded an international outlaw will involve significant reputational costs for Beijing. It will undermine China’s narrative that it is a responsible rising power that deserves a greater hand in global governance. It will make other countries wary of Chinese commitments and will drive regional states even closer to Tokyo and Washington.

These costs to Beijing could make an eventual political compromise more appealing. China might agree to redefine the nine-dash line based on UNCLOS rather than historic rights and enter real negotiations in exchange for the Philippines dropping the case (which will remain open until both parties abide by the award) and agreeing to undertake joint economic development.

In order to promote that kind of political compromise, Manila and Washington will need to embark on a sustained campaign to garner international support for the tribunal’s ruling. That support will need to come not only from like-minded countries like Australia, Japan, and European states, but also from the Philippines’ Southeast Asian neighbors.

China’s first civilian test flights landed at Fiery Cross Reef at the end of 2015, marking the completion of China’s first operational runway in the Spratly Islands. Additional airstrips at Subi Reef and Mischief Reef will soon join it, if they have not already, and military test flights to the features are expected in the first half of 2016. Meanwhile China continues to build port facilities, support structures, and radar installations to support substantial air, naval, and coast guard forces on rotation at these and four other features in the Spratlys. Add to this ongoing military upgrades at Woody Island, where China boasts another airstrip and recently deployed mobile surface-to-air missiles, and it is clear that 2016 will see the capabilities of Chinese forces in the South China Sea increase substantially.

The most direct victims of this increase in Chinese forces over the course of 2016 will be the naval, coast guard, and civilian fleets of Southeast Asian claimants. Simple arithmetic suggests that this year will see more frequent harassment of and clashes with Filipino, Malaysian, and Vietnamese fishermen, oil and gas exploration vessels, and military ships and planes as China increases its capacity to patrol more of the South China Sea and interdict vessels operating in what Beijing considers its sovereign space.

Increased Chinese naval and air capabilities in the South China Sea are already leading to calls from Southeast Asian claimants for greater involvement by outside powers. These voices will only grow louder as 2016 progresses and more Chinese facilities in the Spratlys come online. Already Australia has stepped up patrols under its Operation Gateway—an ongoing mission to patrol Southeast Asian waters and airspace—as the United States increases the frequency of its freedom of navigation patrols in the area.

Japan is stepping up defense cooperation with regional partners, especially Australia and the Philippines, under its new defense guidelines and is hotly debating a larger role in patrolling the South China Sea. And the Indian navy is increasingly operating in the area while emerging as a key provider of arms and equipment to Vietnam and an increasingly important security partner to Australia, Japan, and the United States.

The ability of the United States to boost its intelligence, surveillance, reconnaissance, and patrol capabilities in the South China Sea, and to respond in case of threats to the Philippines or other regional partners, will be significantly increased by the Philippine Supreme Court’s approval in January of the Enhanced Defense Cooperation Agreement. In the coming months, Manila and Washington will finalize the official list of Philippine military facilities to which U.S. forces will gain access as part of the agreement, and at which the United States will invest substantially to improve Philippine military infrastructure.

Given these dynamics, 2016 promises to be a much tenser year in the South China Sea, and one in which the groundwork could be laid for a sustained multilateral campaign to deter further Chinese aggression, support Southeast Asian states in pursuit of their rights, and reach an eventual political compromise to manage the disputes.

This essay originally appeared on CogitAsia, a blog of the CSIS Asia Program.

About Gregory Poling

Gregory B. Poling is senior fellow for Southeast Asia and director of the Asia Maritime Transparency Initiative at CSIS. He oversees research on U.S. foreign policy in the Asia Pacific, with a focus on the maritime domain and the countries of Southeast Asia. His research interests include the South China Sea disputes, democratization in Southeast Asia, and Asian multilateralism.