Arunasalam Thangathurai (Tamil: ; 17 January 1936 5 July 1997) was a Sri Lankan Tamil lawyer, politician and Member of Parliament.

The Sri Lankan Civil War (Sinhala: ශ්‍රී ලංකාවේ සිවිල් යුද්ධය; Tamil: இலங்கை உள்நாட்டுப் போர், Ilaṅkai uḷnāṭṭup pōr) was a civil war fought in Sri Lanka from 1983 to 2009. Beginning on 23 July 1983, there was an intermittent insurgency against the government by the Velupillai Prabhakaran-led Liberation Tigers of Tamil Eelam (LTTE, also known as the Tamil Tigers). The LTTE fought to create an independent Tamil state called Tamil Eelam in the north-east of the island, due to the continuous discrimination and violent persecution against Sri Lankan Tamils by the Sinhalese dominated Sri Lankan Government.Violent persecution erupted in the form of the 1956, 1958, 1977, 1981 and 1983 anti-Tamil pogroms, as well as the 1981 burning of the Jaffna Public Library. These were carried out by the majority Sinhalese mobs often with state support, in the years following Sri Lanka's independence from the British Empire in 1948. Shortly after gaining independence, Sinhala was recognized as the sole official language of the nation. After a 26-year military campaign, the Sri Lankan Armed Forces militarily defeated the Tamil Tigers in May 2009, bringing the civil war to an end.An estimated 70,000 had been killed by 2007. Immediately following the end of the war, on 20 May 2009, the United Nations estimated a total of 80,000–100,000 deaths. However, in 2011, referring to the final phase of the war in 2009, the Report of the Secretary-General's Panel of Experts on Accountability in Sri Lanka stated, “A number of credible sources have estimated that there could have been as many as 40,000 civilian deaths.”Other sources quoting discrepancies in the census figures state that up to 140,000 people were unaccounted for during this period alone. In 2012, the Secretary-General's Internal Review Panel on United Nations Action in Sri Lanka stated, 'The Panel of Experts stated that "[a] number of credible sources have estimated that there could have been as many as 40,000 civilian deaths" while some Government sources state the number was well below 10,000. Other sources have referred to credible information indicating that over 70,000 people are unaccounted for.'The Sri Lankan government has repeatedly refused an independent, international investigation to ascertain the full impact of the war, with some reports claiming that government forces were raping and torturing Tamils involved in collating deaths and disappearances. A military whistleblower accused government forces of a cover up with bodies being buried in mass graves and chemicals being used to dissolve skeletons.During the early part of the conflict, the Sri Lankan forces attempted to retake the areas captured by the LTTE. The tactics employed by the Liberation Tigers of Tamil Eelam against the actions of Government forces resulted in their listing as a terrorist organisation in 33 countries, including the United States, India, Canada and the member nations of the European Union. The Sri Lankan government forces have also been accused of human rights abuses, systematic impunity for serious human rights violations, lack of respect for habeas corpus in arbitrary detentions, and forced disappearances.After two decades of fighting and four failed tries at peace talks, including the deployment of the Indian Army, the Indian Peace Keeping Force from 1987 to 1990, a lasting negotiated settlement to the conflict appeared possible when a cease-fire was declared in December 2001, and a ceasefire agreement signed with international mediation in 2002. However, limited hostilities renewed in late 2005 and the conflict began to escalate until the government launched a number of major military offensives against the LTTE beginning in July 2006, driving the LTTE out of the entire Eastern province of the island. The LTTE then declared they would "resume their freedom struggle to achieve statehood".In 2007, the government shifted its offensive to the north of the country, and formally announced its withdrawal from the ceasefire agreement on 2 January 2008, alleging that the LTTE violated the agreement over 10,000 times. Since then, aided by the destruction of a number of large arms smuggling vessels that belonged to the LTTE, and an international crackdown on the funding for the Tamil Tigers, the government took control of the entire area previously controlled by the Tamil Tigers, including their de facto capital Kilinochchi, main military base Mullaitivu and the entire A9 highway, leading the LTTE to finally admit defeat on 17 May 2009. Following the LTTE's defeat, pro-LTTE Tamil National Alliance dropped its demand for a separate state, in favour of a federal solution. In May 2010, Mahinda Rajapaksa, the then president of Sri Lanka, appointed the Lessons Learnt and Reconciliation Commission (LLRC) to assess the conflict between the time of the ceasefire agreement in 2002 and the defeat of the LTTE in 2009.Since the end of the civil war, the Sri Lankan state has been subject to much global criticism for violating human rights as a result of committing war crimes through bombing civilian targets, usage of heavy weaponry, the abduction and massacres of Sri Lankan Tamils and sexual violence. The LTTE gained notoriety for carrying out numerous attacks against civilians of all ethnicities, particularly those of Sinhalese and Sri Lankan Muslim ethnicity, using child soldiers, assassinations of politicians and human rights activists, and the use of suicide bombings primarily against military targets. British mercenaries who worked for the private military contractor Keenie Meenie Services, which trained the Special Task Force of the Sri Lanka Police, were investigated by the Metropolitan Police for war crimes.The end of the war and victims are remembered in Remembrance Day and Mullivaikkal Remembrance Day.