There are fears of more tension and competition in the South China Sea this year as Beijing continues its relentless building and military operations, with warnings the area will be "saturated with Chinese vessels".
US forces and allies including Australia will keep up their presence in the contested waters, where huge gas projects, commercial fishing, seabed resources and busy trade routes are all at stake.
On top of that are the strategic military concerns.
Here's a look at what's been happening in the region, and what's expected in 2023.
Why is the area contested?
The South China Sea is of great commercial and strategic interest to Indonesia, Malaysia, Philippines, Vietnam, Taiwan and Brunei but has been almost entirely claimed by China.
There's plenty of fish to be caught, and oil and gas opportunities they are all keen to exploit.
It's these overlapping territorial claims that make the 3.3-million-square-kilometres area one of the most contested maritime regions in the world, John Blaxland, professor of International Security and Intelligence Studies at the Australian National University, told the ABC.
"Really what's driving these different disputes is first, the need for these states to access resources," La Trobe Asia director Bec Strating said.
International agreements have attempted to establish boundaries and give a clearer picture as to which country has the rights to certain areas.
China sees things differently and essentially ignores the 1982 United Nations Convention on the Law of the Sea.
China asserts its territorial rights in the South China Sea with a vague, U-shaped "nine-dash line".
It was first drawn in 1947 and since then China has used a series of legal arguments and its presence in the region to assert its claim.
Dr Strating said the nine-dash line and what China was claiming under it was deliberately ambiguous.
She said China had a "grey zone strategy" that made it difficult to interpret what China claims and whether or not those claims have any basis in international law.
"It uses sort of quasi-legal justifications to justify the claims but in a way that doesn't necessarily accord or match up with international law," she said.
"The quasi-legal justification is a form of lawfare, and it is designed to confuse people as to what is a legitimate argument."
The area claimed by China covers swathes of Vietnam's exclusive economic zone (EEZ) and overlaps the EEZs of Brunei, Indonesia, Malaysia, the Philippines and Taiwan.
It also includes the Paracel Islands and Spratly Islands — important dots of land which are becoming increasingly militarised.
"The nine-dash line in the South China Sea gives China, in their books, legitimacy to claim the seabed resources and the protein stocks of the South China Sea," Professor Blaxland said.
Most countries acknowledge each other's EEZs, which extend up to 200 nautical miles from coastlines.
But China's claims go much further over the resource-rich waters, through which an estimated third of global shipping, or $4.84 trillion worth of trade, passes each year.
"They've built up a navy, a coast guard, a maritime militia and an armed fishing fleet to assert their claim and that has been backed up by the manufacturing of a variety of islands that's given them a series of military bases from which they can assert their claims and intimidate the neighbours into backing off," Professor Blaxland said.
China has tried to effectively annex the whole South China Sea region as its territorial waters, according to Malcolm Davis, a senior analyst at the Australian Strategic Policy Institute (ASPI).
"They've created these artificial islands and then claimed them as Chinese territory and put Chinese military bases on those reefs and rocks," he told the ABC.
Despite the conflicting claims, countries are pushing ahead with projects and recently Indonesia announced a huge new gas project in an area China sees as its own.
Billions in energy projects
Indonesia has started to move forward with its $US3 billion ($4.2 billion) offshore gas project near the Natuna Islands, which sit atop one of the largest gas fields in the world located in the waters between Indonesia, Malaysia and Vietnam.
"There will be activity in the border area, which is one of the world's geopolitical hotspots," Dwi Soetjipto, the chairman of Indonesia's oil and gas regulator, said.
"The Indonesian Navy will also participate in securing the upstream oil and gas project so that economically and politically, it becomes an affirmation of Indonesia's sovereignty."
Those remarks were aimed at China and Professor Blaxland said even though the Natuna Islands were in Indonesia's EEZ, it was a difficult area for such a project.
"Because China is persistent and growing in the number of vessels that it uses to be persistent in its intervention, in its harassment, in its assertion of its claims," he said.
In January, Indonesia deployed a warship to its North Natuna Sea to monitor a Chinese coast guard vessel that has been active in the area, which both countries claim as their own.
Exactly how Indonesia would respond further to any moves from China depends somewhat on domestic politics, and what steps President Joko Widodo takes as he looks to anoint a successor.
"There are factors both for and against Indonesia being more militant about its approach, because it has an interest in seeing greater Chinese investment," Professor Blaxland said.
China and Indonesia have worked together on infrastructure projects but they would not find it easy to jointly develop the Natuna Island gas field, Dr Strating said.
"Indonesia — its narratives around the maritime area that it claims in the South China Sea is really also linked to sovereignty, so linked to its sense of national identity," Dr Strating told the ABC.
"It wouldn't want to see its rights being eroded through some sort of joint development scheme with China in that particular area."
Incidents between Chinese fishing fleets and Indonesia's coast guard and navy have occurred already, as Indonesia tried to prevent illegal fishing in its waters, Dr Davis said.
"And there is concern that if the Chinese are allowed to control the Spratly Islands in the South China Sea, basically impose their will, then the next step would be to extend that control south towards Natuna and basically grab the Natunas from Indonesia," he said.
Vietnam building up presence
China and Vietnam in particular have been steadily expanding their reach, using earthmoving equipment to dredge and build artificial islands — more land for bases and runways.
In the last six months, Vietnam has dredged and shifted enough landfill to create about 420 acres of new land across its outposts in the Spratly Islands.
"Vietnam’s dredging and landfill activities in 2022 are substantial and signal an intent to significantly fortify its occupied features in the Spratlys," according to a report the Asia Maritime Transparency Initiative (AMTI) published in December.
Vietnam has been busy in the South China Sea, but its efforts have been dwarfed by China's activity.
From 2013 to 2016, China created more than 3,200 acres of land, according to AMTI, and it has not slowed down.
"China is operating on an order of magnitude greater — 10 times greater [than Vietnam] in terms of its expansion," Professor Blaxland said.
It has spent the past eight years building shoals and reefs into land for strategic and military purposes, Dr Strating said.
"So in being able to control the South China Sea militarily and being able to use land features for runways and for surveillance and for things like that," she said.
"China hopes to be able to protect its own coast, protect its own mainland, by having the South China Sea basically as a buffer."
Both China and Vietnam have claimed the Spratly Islands and experts say Vietnam's building of land features was a direct response to China's activity.
Growing concerns in the Philippines
Under former president Rodrigo Duterte, the Philippines for the most part was keen to keep a close and cosy economic relationship with China.
It did successfully challenge China's nine-dash line at a tribunal at The Hague, which ruled in 2016 that China has no "historic title" over the waters.
But the Philippines never used the 2016 tribunal ruling to push back against China's claim.
Experts say things are unlikely to be the same under President Ferdinand Marcos Jr.
The Philippines on Thursday announced it had given the US more access to its military bases due to mounting concern over China's increasing assertiveness in the South China Sea.
"Manila is far less accommodating of Beijing than it was under Duterte," Dr Davis said.
"China's becoming more aggressive, more assertive, and so some ASEAN states are beginning to push back."
In a meeting with his Chinese counterpart, Xi Jinping, in Beijing last month, Mr Marcos Jr expressed willingness to revive failed negotiations for joint oil exploration.
"But states are concerned that if they do go down this path of cooperation [with China], that it might end up eroding the rights that they have under international law of the sea," Dr Davis said.
Tensions between Beijing and Manila over the South China Sea rose in 2021 after the Philippines' foreign secretary published an obscene tweet telling Chinese ships to leave the disputed waters.
Relations have been strained further by the presence of hundreds of Chinese vessels inside the Philippines' EEZ.
How is 2023 shaping up?
Tensions and competition across the South China Sea could increase as countries expand military and energy programs over the region, Dr Strating said.
In the coming year, she will be watching to see if there is an increase in "dangerous manoeuvres" by aircraft and water vessels, as she expects US forces and allies including Australia to continue operations in the area.
Dr Strating said there also could be movement on a stalled code of conduct agreement between ASEAN and China, which has been in the works for about two decades.
While Professor Blaxland expects a "softer, gentler facade" in Chinese foreign policy as it shifts from its "wolf warrior diplomacy", he doesn't think there will be any slowing down of operations in the South China Sea.
"The operational tempo of Chinese maritime militia and so on precedes relentlessly," he said.
"They continue to basically saturate the South China Sea with Chinese vessels, making it increasingly difficult for the other claimant states to assert their fishing and other economic rights."
Dr Davis said it was likely there would be "more competition, more tension, potential for more incidents occurring in the South China Sea".
