With more than 22,117 kilometres of borders with 14 different countries, China has numerous overlapping territorial claims with its neighbours.

Key points: China has steadily resolved most of its old land disputes in order to focus on India and sea zones

China has steadily resolved most of its old land disputes in order to focus on India and sea zones As recently as 2017 India and China came close to armed conflict over disputed zones

As recently as 2017 India and China came close to armed conflict over disputed zones As China's power grows, it is increasingly confident in challenging its neighbours

Since 1949, the People's Republic of China has laid claim to numerous areas of land ranging from tiny islands right through to whole provinces — much to the chagrin of its neighbours.

Some of these disputes were solved amicably, others resulted in all-out war, and many continue to simmer.

As the country's economic power has risen, so too has its spending on its armed forces, which it increasingly deploys to further its territorial claims.

According to Asia security expert Nick Bisley from La Trobe University, China's core interests have changed substantially since the 1950s, and its assertiveness and ambition have increased significantly — as have the resources at its disposal.

"From the mid-1980s onwards, China moved away from previous Maoist foreign policy and decided in the interests of getting on with its neighbours to resolve all of the disputed land-based borders, and did so with pretty much everyone except India," he told the ABC.

"They essentially said 'let's be pragmatic and bury our differences', which freed them up to look at other areas of more importance like the sea.

A Chinese H-6K bomber patrols in the South China Sea where China has ramped up its military activities. ( AP: Liu Rui/Xinhua )

"Particularly since the 2000s the maritime disputes have taken on a much higher strategic importance and symbolic importance and that is the disputes between Japan in the East China Sea, obviously Taiwan, and then the South China Sea dispute."

Along with growing economic and military clout, Professor Bisley said an increasingly self-assured leadership had enabled China to take more risks and feel more confident in its foreign policy than in the past.

"China has been led by increasingly competent and ambitious people who have taken a much sharper-edged approach to Chinese foreign policy. There is a much greater risk appetite, but there is a caveat to that in terms of the risk of war and escalation — they are not crazy.

"The modus operandi seems to be push as you can, see how strong the reaction is, and push as hard as you can until you get sufficient reaction and say, 'OK, that's probably where the line is at' and then they don't go too far.

"It's often quite a reactive approach but, as is often the case with China, trying to see inside the Chinese black box to understand what is going on in terms of their thinking is very difficult."

Renegade provinces and medieval claims

China maintains that Taiwan and the islands it controls belong to the People's Republic. ( ABC News: Illustration/Jarrod Fankhauser )

Perhaps the most volatile of all China's territorial disputes is the island of Taiwan.

Taiwan was where the defeated Kuomintang nationalist government of the former Republic of China retreated after defeat by Communist Party forces in the Chinese Civil War, which followed the end of World War II.

The former nationalist government never relinquished its claim to be the legitimate ruler of all of China, but in reality, was left in control of just Taiwan island and a few island chains off the mainland, including Kinmen Island, the Wuqiu islands, the Penghu islands, and the Matsu Islands.

Chinese naval forces maintain a substantial presence in the contested South China Sea. ( Reuters: China Daily )

At various points in the 20th century both sides have fired shells at the other. In more recent years Taiwan has accused China of intimidation and threats after Chinese military jets conducted flights around Taiwan and also for testing missiles in the region.

China maintains that Taiwan is a renegade province, and under its One China policy intends to return the islands to Beijing's control.

Taiwan has not declared itself independent, but current President Tsai Ing-wen has stated her Government wishes to maintain the status quo, despite her Democratic Progressive Party being strongly in favour of gaining independence from China.

A map showing Senkaku islands, which are controlled by Japan but are also claimed by China and Taiwan. ( ABC News: Illustration/Jarrod Fankhauser )

Also of strategic and economic importance are the Senkaku Islands, situated just to the north-east of Taiwan in the East China Sea, which are claimed by China, Japan and Taiwan.

The islands are currently controlled by Japan and are uninhabited. Discoveries of potential oil reserves led to competing claims from the three countries.

Japan Coast Guard vessel PS206 Houou sails in front of Uotsuri island, one of the disputed islands, called Senkaku in Japan and Diaoyu in China, in the East China Sea August 18, 2013. Boats carrying about 20 members of a Japanese nationalist group headed back to port on Sunday after sailing near tiny islands in the East China Sea that are at the centre of a dispute between Japan and China. ( Reuters: Ruairidh Villar )

The basis of China's claims is that it discovered the islands in the Middle Ages. However, the islands were later controlled by Japan from 1895 until the end of World War II and again after the United States transferred them back to Japan in 1972.

Reefs, rocks and atolls

The South China Sea is home to many atolls, with multiple competing claims. ( ABC News: Illustration/Jarrod Fankhauser )

Of all the disputed areas claimed by China, none has been more high-profile in recent years or involved more players than the South China Sea.

There are no less than six countries with competing claims, with many other countries weighing in due to the area's strategic importance as one of the world's busiest shipping lanes.

The region contains two island groups, the Paracel and Spratly islands, many of which are small reefs and atolls.

China, Vietnam, Malaysia, Brunei, The Philippines, and Taiwan all claim parts or all of the region, with each having established a presence in parts of the area.

Tensions have increased as all countries have begun to establish military presences on the islands, with China the most active. As a result, other nations like the US and its allies have increased naval exercises in the region in the name of freedom of navigation.

Professor Bisley said the rise of China and its growing desire to exert its influence on the region had seen countries increasingly staking their claims in the South China Sea by building military bases and other facilities.

"Certainly, with the South China Sea area China has more at stake at sea than it used to — it is far more dependent upon maritime approaches now so China now has a much greater interest in who controls the region and in protecting its maritime approaches," he said.

Under President Xi Jinping, China has increased its activities in the South China Sea. ( Xinhua via AP )

"From around 2010-11 and especially in 2015-16, you saw the island-building in the South China Sea and that's now basically stopped — China got largely what they wanted, and partly because the US and its allies have pushed back and said 'We are not happy about this', I think China has now figured it has gone as far as it wants to go.

"It could push a little further but then you are getting into very risky territory."

'Let's see how far we can go'

The disputed areas along the borders between China, Pakistan, India and Bhutan. ( ABC News: Illustration/Jarrod Fankhauser )

After Taiwan, India is perhaps the most volatile of China's borders and one of its longest at 3,380 kilometres.

China claims a number of areas along its border with India, including Arunachal Pradesh and Aksai Chin. It also claims parcels of land that Nepal and Bhutan say are, in fact, their territory.

While China may have resolved its differences with other neighbours, the Indian border remains volatile, said Professor Bisley.

"Unlike the other land disputes, it's a very large and strategically significant border where they fought a war in 1962," he said.

"Over time China has become more assertive in the way it approaches its claims in the area."

With so much of the Chinese-Indian border impassable terrain, such as the Himalayas, strategic points are strongly contested. ( NASA Johnson )

In 1962, China attacked India in both the west and east of the country's borders along disputed zones, eventually defeating India and taking control of Aksai Chin before a ceasefire was agreed.

Given the length of the borders and the fact that both are rising Asian powers with nuclear weapons, many fear the possibility that a border clash could slip into another all-out war.

As recently as 2017 border tensions came close to war between the two rising Asian superpowers.

The standoff occurred after China began constructing a road near the Bhutanese border in the strategically sensitive Doklam Plateau area, claimed by China and Bhutan.

Both Bhutan and India protested the road-building to China before Indian and Chinese soldiers engaged in a tense standoff along the disputed area. The troops later stood down and China ceased construction work.

Professor Bisley said China was testing its rival India but had underestimated the strength of the Indian Government's response.

"I actually think China was surprised by India's response; they were pushing and thinking 'let's see how far we can go', but they were caught off-guard by the consistency and the tenacity of the Indians," he said.

"I think they had anticipated it would be more like the South China Sea where countries were initially reluctant to take any risks as China expanded its activities."

Chinese troops hold a banner that reads "You've crossed the border, please go back" at the disputed border with India. ( AP, file photo )

Pakistan and Russia, the friendly disputes

China's border dispute with Pakistan is one that ended with a peaceful outcome. Both sides claimed thousands of square kilometres of territory along their mountainous border.

However, in 1962, in exchange for Pakistan recognising China's seat at the United Nations, the two signed an agreement where Pakistan ceded a portion of the disputed territory to China, while China recognises Pakistan's control over the remaining portion.

The agreement brought the two countries closer together politically, militarily and economically, much to the annoyance of traditional rival India and Washington, which competes for influence in the region with Beijing.

The island of Zhenbao lies in the Ussuri River, which forms the border between China and Russia. ( Supplied: Wikicommons/TowerCard )

China and Russia, then the Soviet Union, were for a time allies during the Cold War before they drifted apart ideologically.

Tensions rose and eventually came to a head when hostilities broke out in a 1969 dispute over the tiny river island of Zhenbao, situated between Russian Siberia and Chinese Manchuria.

Fighting took place over several months, with a total of 100 casualties, before a ceasefire was called. There was no firm agreement on the island's fate until a border agreement acknowledging China's ownership of the island was signed in 1991.