The Nine-Dash Line: China’s Cause For Aggression In The Pacific • The Havok Journal (2024)

by Nick Weber

The world is becoming more attuned to the reality that the People’s Republic of China is a threat to peace and stability, not only in the Indo-Pacific, but across the globe. In the United States, this is understood. But that understanding is colloquial at best. Americans know China is big, strong, or that it has stolen a lot of technology from us. We also know that the Chinese Communist Party (CCP) wants to invade Taiwan (which means we might go to war someday). But other than that, the history – and resulting motivations – behind China’s growing grasp for dominance in the Indo-Pacific is entirely foreign to most Americans.

Let’s change that.

Taiwan is China’s principal target. Today, the island nation offers China increased economic opportunity, geopolitical positioning, and an improved ability to project naval power into the Pacific. But China’s true desire for seizing Taiwan lies in the past. Specifically, the Chinese Civil War which saw the Kuomintang nationalists flee to Taiwan in defeat and establish the Republic of China. The CCP’s greatest adversary, and only viable claimant to Chinese sovereignty, persists on Taiwan today.

But China’s military exercises, patrols, and displays of aggression are not – and have not – been reserved for Taiwan. Recently, Japan reported more than 200 consecutive days of Chinese patrols around Japanese islands.[1] In the Philippine’s, a naval encounter got violent at the Ayungin Shoal.[2]

So, what exactly are China’s claims, beyond Taiwan, in the Indo-Pacific? And where do those claims originate? Once again, we have to look to the past.

In 1935, nearing what would be the end of the first phase of the Chinese Civil War, the Republic of China (the eventual Taiwanese nationalists) published a map titled “Map of Chinese Islands in the South China Sea.” The map featured an eleven-dashed line that encircled all of the Chinese claims within the South China Sea. It included some islands that are, today, some of the most hotly contested pieces of territory in our global gray zone competition; the Paracel and Spratly Islands.

During World War II and the Post-War Period, the map received a few revisions. It’s greatest, however, was the 1952 revision by Mao Zedong which saw the removal of claims on the Gulf of Tonkin – an alleged gesture to the newly formed North Vietnam.[3]

And so, Mao’s revisions became what is now known as the “Nine-Dash Line,” China’s formal claims within the South China Sea, and its self-imposed legal basis for aggression across the region.

The CCP’s use of the Nine-Dash Line has been confusing, mostly due to some inconsistencies in claims or varied versions of maps.[4]^,[5] But the CCP does consistently use it as a sort of stand-by cassus belli.

So why exactly is the CCP so set on seizing these islands? Why are they so valuable? Two glaring advantages explain why the Chinese want to, eventually, secure island claims in the South China Sea.

The first is security. China is constructing a navy to contend with the United States in the Indo-Pacific.[6] They are also constructing a modern air force and rocket force in support. By securing islands throughout the South China Sea (which is within the First Island China) the Chinese can disperse forces and better position themselves for American intervention (which might look like a slight update to World War II’s island hopping strategy).

The second reason is more vague. It is related to economics, power projection, and China’s status as a regional hegemon. If you look at maps of the Nine-Dash Line, you will notice how extensive the territory is. China’s claim also includes the maritime routes, which would allow the CCP to effectively control and manipulate maritime traffic in the Pacific. For reference, the trade that goes through the South China Sea accounts for 60% of all maritime trade, and 22% percent of global trade entirely.[7]

By securing territory identified in the Nine-Dash Line map, the CCP would effectively be setting the conditions to be the Indo-Pacific’s regional hegemon, unseating the United States and ultimately beginning the reshaping of partnerships in the Pacific.

There is still no certainty as to when, or to what degree of effectiveness, the Chinese would invade Taiwan. There is equally less certainty as to whether or not the PLA Navy would enforce its claims. A 2021 law passed by the CCP allows Chinese Coast Guard vessels to use force to back sovereignty claims at sea.[8] In the case of other contested claims, such as with Vietnam, China may turn to diplomacy to gain concessions.

There is no certainty as to how China will pursue these goals, or when. Only that their claim is strong, and the capabilities are growing.

_______________________

Nick Weber is an officer in the Marine Corps Reserves. His experience includes air command and control operations in the Indo-Pacific. He is a Master’s student of Applied Intelligence and currently writes “The Intel Brief,” a curated foreign policy and national security newsletter for military, business, and academic professionals.

[1] https://www.newsweek.com/china-coast-guard-sets-record-patrol-senkaku-diaoyu-islands-1923703

[2] https://news.abs-cbn.com/news/2024/6/19/watch-china-coast-guard-rams-ph-boat-during-last-ayungin-mission-1331

[3] https://thediplomat.com/2013/08/history-the-weak-link-in-beijings-maritime-claims/

[4] https://web.archive.org/web/20130929225126/http://www.rusi.org/publications/newsbrief/ref%3AA5225D72CD72F8/

[5] https://2009-2017.state.gov/documents/organization/234936.pdf

[6] https://nationalinterest.org/blog/buzz/chinas-subs-can-track-navy-aircraft-carriers-sink-them-211547

[7] https://www.linkedin.com/pulse/short-overview-economic-importance-south-china-sea-scs-gr%C3%BCnhaupt-mjcxe/

[8] https://www.csis.org/analysis/responding-more-coercive-chinese-coast-guard-and-potential-prc-quarantine-taiwan#:~:text=In%202021%2C%20China%20passed%20the,%E2%80%9Cviolate%E2%80%9D%20Chinese%20domestic%20law.