{{Use dmy dates|date=February 2020}} {{EngvarB|date=July 2020}} {{Infobox river | name = Sumdorong Chu | name_native = {{native name|bo|གསུམ་རྡོ་རོང་ཆུ}} | name_other = | name_etymology = | nickname = <!---------------------- IMAGE--> | image = | image_size = | image_caption = | image_alt = <!---------------------- MAPS --> | pushpin_map = Tibet#India Arunachal Pradesh | pushpin_map_size = | pushpin_map_caption = Mouth of Sumdorong Chu in Nyamjang Chu | pushpin_map_alt = | pushpin_map_relief = 0 <!---------------------- LOCATION --> | subdivision_type1 = Country | subdivision_name1 = China; India | subdivision_type2 = Region | subdivision_name2 = Shannan, Tibet; Arunachal Pradesh | subdivision_type3 = District | subdivision_name3 = Tsona County; Tawang district | subdivision_type4 = City | subdivision_name4 = Lė Township; Zemithang Circle | subdivision_type5 = | subdivision_name5 = <!---------------------- BASIN FEATURES --> | source1 = Eastern Himalayas | source1_location = Lė Township | source1_coordinates = {{coord|27.7956|91.8216|format=dms}} | source1_elevation = {{convert|4600|m|ft|abbr=on}} | mouth = Nyamjang Chu valley | mouth_location = | mouth_coordinates = {{coord|27.80|91.745|format=dms|display=inline,title}} | mouth_elevation = {{convert|2350|m|ft|abbr=on}} | progression = Nyamjang Chu, Tawang Chu, Manas River | river_system = Brahmaputra | extra = }} '''Sumdorong Chu''' ({{bo|t=གསུམ་རྡོ་རོང་ཆུ|w=gsum rdo rong chu}}; {{zh|c=桑多洛河|p=Sāng duō luò hé}})<ref>{{cite web |title=India-China Border Dispute |website=GlobalSecurity.org |url=https://www.globalsecurity.org/military/world/war/india-china_conflicts.htm |access-date=1 August 2017}}</ref> is a tributary of the Nyamjang Chu river that flows along the disputed Sino-Indian border between the Tsona County of Tibet and the Tawang district of Arunachal Pradesh. It originates in the Tokpo Shiri Glacier, about 7–10&nbsp;kilometres east of Nyamjang Chu, and flows down to the river.<ref>"Chinese troops in Kameng", ''The Hindustan Times'', 17 July 1986, in {{harvp|China and South Asia|1987}}.</ref> Its junction with Nyamjang Chu is about two kilometers to the north of that of Namka Chu, another contested river valley.

The Sumdorong Chu valley was the site of a standoff between India and China in 1986–1987 which, despite giving rise to the fears of another war, deescalated successfully. Subsequently, India and China formulated agreements for managing future border tensions.<ref>{{cite web |author=V. Natarajan |title=The Sumdorong Chu Incident |website=Bharat Rakshak |url=https://www.bharat-rakshak.com/ARMY/history/siachen/286-Sumdorong-Incident.html |date=12 October 2006 |access-date=1 August 2017}}</ref>{{sfnp|Pardesi, Managing the Sumdorong Chu Crisis|2020}}

== Location == Sumdorong Chu flows in a disputed border region between Tibet's Tsona County and Arunachal Pradesh's Tawang district. The dispute arises due to differing interpretations of where the McMahon Line lies.

China adheres to the 1914 map of the McMahon Line, which shows the border as a straight line at 27°44'30" N latitude till the range of "Menlakathong La" (roughly the modern Bum La Pass).<ref>A. G. Noorani, [https://frontline.thehindu.com/world-affairs/article30218522.ece Perseverance in peace process], Frontline, 29 August 2003.</ref> India believes that the true border lies along the highest watershed line in the region, which is to the north of the Namka Chu and Sumdorong Chu streams.<ref>[https://bhuvan-app1.nrsc.gov.in/bhuvan2d/bhuvan/bhuvan2d.php Bhuvan, Indian Geo-Platform of ISRO], search key: "Kenze Mane,ARUNACHAL PRADESH", retrieved 13 July 2020.</ref>

== 1987 standoff == {{main|Sumdorong Chu standoff}} thumb|right|260px|Sumdorong Chu and vicinity In 1986–87, a military standoff took in the Sumdorong Chu Valley. It was initiated by China moving a company of troops to Wangdung, a pasture to the south of Sumdorong Chu which India held to be part of its territory. The Indian troops stood their ground on the neighbouring Lungro la ridge and both the sides moved a large number of troops to the border. The crisis was diffused after the visit of Indian Foreign Minister to Beijing in May 1987.

==See also== * Namka Chu * McMahon Line

==References== {{Reflist}}

==Bibliography== {{refbegin}} *{{cite journal | title = China and South Asia (July–September 1986) | journal = China Report | date = February 1987 | volume = 23 | issue = 1 | pages = 113–139 | doi = 10.1177/000944558702300111 | issn = 0009-4455 | s2cid = 220874000 | ref = {{sfnref|China and South Asia|1987}} }} *{{cite book| title = Strong Borders, Secure Nation: Cooperation and Conflict in China's Territorial Disputes | last = Fravel | first = M. Taylor | publisher = Princeton University Press | url = https://books.google.com/books?id=02Hjr6RUckwC | date = 2008 | isbn = 978-1-4008-2887-6 | ref = {{sfnref|Fravel, Strong Borders, Secure Nation|2008}} }} *{{cite book| title = India and the China Crisis | last = Hoffmann | first = Steven A. | year = 2018 | orig-year = first published 1990 | publisher = University of California Press | url = https://books.google.com/books?id=_bjADwAAQBAJ | isbn = 978-0-520-06537-6 | ref = {{sfnref|Hoffmann, India and the China Crisis|2018}} }} *{{cite journal | title = Managing the 1986-87 Sino-Indian Sumdorong Chu Crisis | last = Pardesi | first = Manjeet S. | journal = India Review | year = 2020 | volume = 18 | issue = 5 | pages = 534–551 | doi = 10.1080/14736489.2019.1703364 | issn = 1473-6489 | s2cid = 213073300 | ref = {{sfnref|Pardesi, Managing the Sumdorong Chu Crisis|2020}} }} {{refend}}

Category:China–India border Category:Rivers of Arunachal Pradesh Category:Rivers of Tibet Category:Shannan, Tibet Category:Tawang district Category:Territorial disputes of China Category:Territorial disputes of India Category:Borders of Arunachal Pradesh