China–North Korea border

The China–North Korea border is an international border separating China and North Korea, extending from Korea Bay in the west to a tripoint with Russia in the east. The total length of the border is 1,352 kilometers (840 mi). The current border was created by two secret treaties signed between China and North Korea in 1962 and 1964.

Geography
From west to east, the two countries are divided by three significant geographical features: the Yalu River, Paektu Mountain, and the Tumen River.

Dandong, in the Liaoning Province of China, on the Yalu River delta, is the largest city on the border. On the other side of the river is the city of Sinuiju in North Pyongan Province, North Korea. The two cities are situated on the Yalu river delta at the western end of the border, near the Yellow Sea. Their waterfronts face each other and are connected by the Sino-Korean Friendship Bridge.

There are 205 islands on the Yalu River. A 1962 border treaty between North Korea and China split the islands according to which ethnic group were living on each island. North Korea possesses 127 and China 78. Due to the division criteria, some islands such as Hwanggumpyong Island belong to North Korea even though they are on the Chinese side of the river. Both countries have navigation rights on the river, including in the delta.

The source of the Yalu River is Heaven Lake on Paektu Mountain, which is considered the birthplace of the Korean and Manchu peoples. This lake is also the source of the Tumen River which forms the eastern portion of the border.

Pre-modern
Historically the border areas have been contested by successive Chinese and Korean polities, though the current border utilising the Yalu-Tumen rivers appears to have been in place by the mid 15th century. The Manchu (Qing) dynasty of China managed to consolidate control of north-east China (Manchuria) and establish a nebulous 'tributary' rule over Joseon Korea. In 1712 the Chinese Kangxi Emperor and Joseon King Sukjong authorised a border mission to analyse the border alignment in the vicinity of the Yalu-Tumen headwaters on Mount Paektu. A pillar was erected indicating the border alignment in this section, and a demilitarised neutral zone set along the frontier. In 1875 China, fearful of the Russia presence to the east, occupied its section of the neutral zone. A Chinese-Korean boundary team surveyed the Mt Paektu area in 1885–87, however there were disputes over whether the pillar had been moved, and the two sides were unable to agree precisely which of the several headwater streams should form the frontier. In 1889 the Chinese unilaterally demarcated a frontier in the area, marking it with a series of posts, however these were later destroyed by the Koreans. Korea also made periodic claims to Korean-inhabited lands (Jiandao) north of the Tumen.

In the early 20th century Korea came under the increasing influence of Japan, and by 1905 it was deemed a Japanese protectorate. In 1909, China and Japan signed the Gando Convention, whereby Korea was made to renounce any claims north of the Yalu-Tumen line in return for extensive Chinese concessions to Japan. In the Mount Paektu area the 1712 pillar was confirmed as the border marker, and the Shiyi/Sogul headwater stream utilised up to the Tumen border. The following year Japan formally annexed Korea.

Current border
Korea achieved its independence after the 1945 surrender of Japan and subsequently divided into two, and the Chinese Communist Party assumed rule over China after it won the Chinese Civil War in 1949.

In 1962, North Korea and China signed a border treaty in secret which fixed the boundary line along the Yalu and Tumen rivers, with the middle overland section running across Mount Paektu and through Heaven Lake. A subsequent protocol in 1964 allocated the numerous riverine islets, granting 264 to North Korea and 187 to China. These two treaties define the modern border between the two countries.

Trade and contact
North Korea's border with China has been described as its "lifeline to the outside world." Much of the China-North Korea trade goes through the port of Dandong.

Chinese cell phone service has been known to extend as far as 10 km into Korean territory, which has led to the development of a black market for Chinese cell phones in the border regions. International calls are strictly forbidden in North Korea, and violators put themselves at considerable peril to acquire such phones.

Tourists in Dandong can take speedboat rides along the North Korean side of the Amnok River and up its tributaries.

A common wedding day event for some Chinese couples involve renting boats, putting life preservers on over their wedding clothes, and going to the North Korean border to have wedding photos taken.

Memory cards and teddy bears are reportedly among the most popular items for North Koreans shopping in Dandong.

Border security
In 2005, the border between North Korea and China was described as "porous".

The Chinese government transferred responsibility for managing the border to the army from the police in 2003. Chinese authorities began building wire fences "on major defection routes along the Tumen River" in 2003. Beginning in September 2006, China erected a 20 km fence on the border near Dandong, along stretches of the Yalu River delta with lower banks and narrower width. The concrete and barbed wire fence ranged in height from 8 ft to 15 ft.

In 2007 a U.S. official stated that China was building more "fences and installations at key border outposts". In the same year, it was reported that North Korea had started building a fence along a 10 km stretch of its side of the Yalu River, and had also built a road to guard the area.

In 2011 it was reported that China was building fences 4 m high near Dandong, and that 13 km of this new fencing had been built. It was also reported that China was reinforcing patrols, and that new patrol posts were being built on higher ground to give wider visibility over the area. According to a resident of the area: "It's the first time such strong border fences are being erected here. Looks like it is related to the unstable situation in North Korea." The resident also added that previously "anybody could cross if they really wanted" as the fence had only been 10 ft with no barbed wire.

In 2014, an Australian journalist who visited Dandong reported a low level of border security. In 2015, fencing was reported as the exception rather than the rule. In 2015, a photojournalist who traveled along the Chinese side of the border commented that fencing was rare and that it would be easy to cross the Amnok river when it was frozen. The same report noted friendly contact between people on opposite sides of the border. In 2018, a photojournalist drove along the border and described it as "mile after mile of nothing, guarded by no-one".

In 2015, a single rogue North Korean soldier killed four ethnic Korean citizens of China who lived along the border of China with North Korea.

Rumours of Chinese troop mobilizations on the border frequently circulate in times of heightened tension on the Korean peninsula. According to scholar Adam Cathcart, these rumours are hard to substantiate and hard to interpret.

A leaked China Mobile document that went viral on Chinese social media on 7 December 2017 allegedly revealed Chinese government plans to construct five "refugee settlement points" along the border to North Korea in Changbai county and Jilin province. This was apparently in preparation for a large influx of North Korean refugees if the Kim regime collapsed in a potential conflict with the United States. The Guardian quoted the document: "Due to cross-border tensions … the [Communist] party committee and government of Changbai county has proposed setting up five refugee camps in the county."

Border control was significantly strengthened in 2020 due to the COVID-19 pandemic. North Korea closed its border with China in January 2020. By August 2020, the regime had established a 1–2 kilometer buffer zone in front of the border where official permits were required to enter; trespassers would be "fired at without warning". In May 2023, newly constructed double walls and guard posts were observed along hundreds of kilometers of the border, according to satellite photos published by Reuters.