20th century

== Wars and politics ==
{{main|International relations of the Great Powers (1814–1919)|Diplomatic history of World War I|International relations (1919–1939)|Diplomatic history of World War II|Cold War|International relations since 1989}}
[[File:Map Europe 1923-en.svg|thumb|right|Map of territorial changes in Europe after [[World War I]] (as of 1923).]]
The number of people killed during the century by government actions was in the hundreds of millions. This includes deaths caused by wars, genocide, politicide and mass murders. The deaths from acts of war during the two world wars alone have been estimated at between 50 and 80 million.{{Citation needed|date=February 2015|reason=also contradicted by figure of 100m by Tilly, below}} Political scientist [[Rudolph Rummel]] estimated 262,000,000 deaths caused by [[democide]], which excludes those killed in war battles, civilians unintentionally killed in war and killings of rioting mobs.<ref>[http://www.hawaii.edu/powerkills/JCR.ART.HTM Democide] See various exclusions</ref> According to [[Charles Tilly]], "Altogether, about 100 million people died as a direct result of action by organized military units backed by one government or another over the course of the century. Most likely a comparable number of civilians died of war-induced disease and other indirect effects."<ref>Charles Tilly (2003). "''[https://books.google.com/books?id=ycwqpVKx4H4C&pg=PA55 The politics of collective violence]''" Cambridge University Press. p. 55. {{ISBN|0-521-53145-4}}.</ref> It is estimated that approximately 70 million Europeans died through war, violence and famine between 1914 and 1945.<ref>Gary Rodger Weaver (1998). ''Culture, Communication, and Conflict''. Simon & Schuster. p. 474. {{ISBN|0-536-00373-4}}</ref>
* The [[Armenian genocide|Armenian]], [[Seyfo|Syriac]] and [[Greek genocide]] were the systematic destruction, mass murder and expulsion of the [[Armenian people|Armenians]], [[Assyrian people|Assyrians]] and [[Greek people|Greeks]] in the [[Ottoman Empire]] during [[World War&nbsp;I]], spearheaded by the ruling [[Committee of Union and Progress]] (CUP).{{sfn|Suny|2015|pp=245, 330}}{{sfn|Bozarslan|Duclert|Kévorkian|2015|p=187}}
* The [[Alliance of Eight Nations]] ([[Austro-Hungarian Empire]], [[Third French Republic|French Republic]], [[German Empire]], [[Kingdom of Italy]], [[Empire of Japan]], [[Russian Empire]], [[United Kingdom of Great Britain and Ireland]] and [[United States of America]]) formed in 1900 to invade the [[Qing dynasty|Qing China]] represented the club of great powers in the early 20th century.<!-- Moved from lead section 2023-07-12; I am not an expert but this sentence needs review. -->
* Rising [[nationalism]] and increasing national awareness were among the many causes of [[World War I]] (1914–1918), the first of two wars to involve many major world powers including [[German Empire|Germany]], [[French Third Republic|France]], [[Kingdom of Italy|Italy]], [[Empire of Japan|Japan]], [[Russian Empire|Russia]]/[[USSR]], the [[British Empire]] and the [[United States]]. At the time, it was said by many to be the "[[The war to end war|war to end all wars]]".
* The [[Arab Revolt]] of 1916 was an armed uprising against the [[Ottoman Empire]] done by the [[Arabs]] in [[McMahon–Hussein Correspondence|agreement with the British Empire.]] The revolt was led by [[Hussein bin Ali, King of Hejaz|Sharif Hussein bin Ali]] who was promised by [[Henry McMahon]], the British High Commissioner in Egypt, that in exchange for fighting the Ottoman Empire, Sharif Hussein would gain control over all Arab lands under the Ottoman Empire. A promise the British Empire did not honor.<ref>{{Cite journal |last=Sabet |first=Amr G. E. |date=2010-01-01 |title=A History of the Modern Middle East, 4th ed. |journal=American Journal of Islam and Society |volume=27 |issue=1 |pages=122–124 |doi=10.35632/ajis.v27i1.1351 |issn=2690-3741|doi-access=free }}</ref><ref>{{Citation |last1=McMahon |first1=Henry |title=6.2 British Diplomacy: The Hussein-McMahon Letters |date=2022-12-31 |url=http://dx.doi.org/10.18574/nyu/9780814759332.003.0032 |work=The World War I Reader |pages=335–339 |access-date=2023-11-05 |publisher=New York University Press |isbn=978-0-8147-5933-2 |last2=Ali |first2=Hussein Ibn|doi=10.18574/nyu/9780814759332.003.0032 }}</ref><ref>{{Citation |title=The Sykes-Picot Agreement (1916) |date=2009-09-10 |url=http://dx.doi.org/10.4324/9780203871591-10 |work=The Arab-Israeli Conflict |pages=59–60 |access-date=2023-11-05 |publisher=Routledge |doi=10.4324/9780203871591-10 |isbn=978-0-203-87159-1}}</ref>
* During World War I, in the [[Russian Revolution of 1917]], 300 years of [[Russian Tsarist Empire|Tsarist reign]] were ended and the [[Bolsheviks]], under the leadership of [[Vladimir Lenin]], established the world's first [[Communist state]].
* The [[Aftermath of World War I#Territorial gains and losses|end of World War I]] saw the collapse of the [[Central Powers|central powers]], the [[German Empire]], the [[Austria-Hungary|Austrian-Hungarian Empire]], the [[Kingdom of Bulgaria]], and the [[Ottoman Empire]] into several independent sovereign states throughout [[Central Europe]], the [[Balkans]], and the [[Middle East]]. 
* After gaining political rights in the United States and much of Europe in the first part of the century, and with the advent of new [[birth control]] techniques, [[Women's suffrage|women became more independent]] throughout the century.
* [[Industrial warfare]] greatly increased in its scale and complexity during the first half of the 20th century. Notable developments included [[chemical warfare]], the introduction of [[military aviation]] and the widespread use of [[submarines]]. The introduction of [[nuclear warfare]] in the mid-20th century marked the definite transition to [[modern warfare]].
* [[Revolutions of 1917–1923|The Revolutions of 1917-1923]] occurred during and World War I inspired by the Russian Revolution which saw many political changes in Europe and in Asia.
* [[Osage Indian murders|The Osage Murders of 1918-1931]] were a series of killings of members of the Native American [[Osage Nation]], who were the richest people per capita in the world at that time.<ref>{{Cite news |date=1921-06-25 |title=OSAGE ARE RICHEST PEOPLE.; Greatest Per Capita Wealth in World Results From Oil Deal. |language=en-US |work=The New York Times |url=https://www.nytimes.com/1921/06/25/archives/osage-are-richest-people-greatest-per-capita-wealth-in-world.html |access-date=2023-11-05 |issn=0362-4331}}</ref>
* The 1921 [[Tulsa race massacre|Tulsa Race Massacre]], was a racist anti black terrorist attack in the [[Greenwood District, Tulsa|Greenwood District]] in [[Tulsa, Oklahoma]], which was home to many successful and wealthy [[African Americans|Black Americans]]. The attack was perpetrated by white residents and local white deputies. The  perpetrators were armed by local government officials.<ref>Brown, DeNeen L. (October 22, 2019). "HBO's 'Watchmen' depicts a deadly Tulsa race massacre that was all too real". ''Washington Post''. Retrieved July 3, 2020. <q>"White city police officer "deputized" members of the lynch mob and "instructed them to get a gun and get a n-----", according to the Oklahoma Historical Society".</q></ref><ref>"Tulsa race massacre of 1921 | Commission, Facts, & Books". ''Britannica''. Retrieved September 4, 2022.</ref>
* The [[Great Depression]] in the 1930s led to the rise of [[Fascism]] and [[Nazism]] in Europe.
* A violent [[Spanish Civil War|civil war]] broke out in Spain in 1936 when General [[Francisco Franco]] rebelled against the [[Second Spanish Republic]]. Many consider this war as a testing battleground for World War II, as the fascist armies bombed some Spanish territories.
* [[World War II]] (1939–1945) became the deadliest conflict in human history involving primarily the axis, [[Nazi Germany]], [[Fascist Italy (1922–1943)|Fascist Italy]], and the [[Empire of Japan]] against the allies, [[Republic of China (1912–1949)|China]], [[French Third Republic|France]], the [[British Empire|United Kingdom]], the [[Soviet Union]], and the [[United States]]. Many atrocities occurred, particularly [[the Holocaust]] killing approximately 11 million victims. It ended with the [[Atomic bombings of Hiroshima and Nagasaki|atomic bombings on Hiroshima and Nagasaki]] in Japan.
* The two world wars led to efforts to increase [[Multilateralism|international cooperation]], notably through the founding of the [[League of Nations]] after World War I, and its successor, the [[United Nations]], after World War II.
* The [[Israeli Declaration of Independence|creation]] of [[Israel]] in 1948, a Jewish state in the Middle East, at the [[end of the British Mandate for Palestine]], fueled many conflicts between [[Israeli–Palestinian conflict|Israelis and Palestinians]] in addition to [[Arab–Israeli conflict|regional conflicts]]. These were also influenced by the vast oil fields in many of the other countries of the predominantly Arab region.
* In 1948 [[Nakba|The Nakba]] was, according to several historians, a targeted ethnic cleansing campaign against Arabs in Palestine perpetrated by Jewish Militias under [[Plan Dalet|Plan Delta]], a plan ordered by [[David Ben-Gurion|Ben-Gurion]]. The campaign utilized methods of intimidation, violent attacks, and the destruction of several Arab villages.<ref>{{Citation |title=The Palestinian Nakba |url=http://dx.doi.org/10.2307/j.ctt18dztmq.5 |work=The Politics of Denial |pages=7–48 |access-date=2023-11-05 |publisher=Pluto Press|doi=10.2307/j.ctt18dztmq.5 }}</ref><ref>{{Cite web |last=VS |date=2023-11-29 |title=About the Nakba |url=https://www.un.org/unispal/about-the-nakba/ |access-date=2023-11-05 |website=Question of Palestine |language=en-US}}</ref><ref>{{Citation |title=How Palestinians were expelled from their homes |url=https://www.youtube.com/watch?v=rGVgjS98OsU |access-date=2023-11-05 |language=en}}</ref>
* After the [[Soviet Union in World War II|Soviet Union's involvement in World War II]], [[communism]] became a major force in [[global politics]], notably in Eastern Europe, China, [[Indochina]] and [[Cuba]], where [[Communist party|communist parties]] gained near-absolute power. 
[[File:Richard_M._Nixon_and_Leonid_Brezhnev_aboard_the_Sequoia_-_NARA_-_194518.tif|thumb|[[Richard Nixon]] and [[Leonid Brezhnev]] aboard the [[USS Sequoia (presidential yacht)|USS ''Sequoia'']], June 19, 1973]]
* The [[Cold War]] (1947–1991) involved an [[arms race]] and increasing competition between the two major players in the world: the Soviet Union and the United States. This competition included the development and improvement of [[nuclear weapon]]s and [[Space Race|space technology]]. This led to the [[proxy war]]s with the [[Western bloc]], including wars in [[Korean War|Korea]] (1950–1953) and [[Vietnam War|Vietnam]] (1957–1975).
* The [[Human rights in the Soviet Union|Soviet]] authorities caused the deaths of millions of their own citizens to eliminate domestic opposition.<ref>Geoffrey A. Hosking (2001). "''[https://books.google.com/books?id=oh-5AAmboMUC&pg=PA469 Russia and the Russians: a history]''". Harvard University Press. p. 469. {{ISBN|0-674-00473-6}}</ref> More than 18 million people passed through the [[Gulag]], with a further 6 million being [[Population transfer in the Soviet Union#Timeline|exiled]] to remote areas of the [[Soviet Union]].<ref>"[https://query.nytimes.com/gst/fullpage.html?res=9D00EED61F3DF932A25756C0A9659C8B63&sec=&spon=&pagewanted=print The Other Killing Machine]". ''The New York Times''. May 11, 2003</ref>
* [[Nationalism|Nationalist movements]] in the [[Indian subcontinent]] led to the independence and [[Partition of India|partition]] of [[Jawaharlal Nehru]]-led India and [[Muhammad Ali Jinnah]]-led Pakistan, although would lead to [[Indo-Pakistani wars and conflicts|conflicts]] between the two nations such as border and territorial disputes.
* After a [[Century of humiliation|long period]] of civil wars and conflicts with western powers, China's [[Qing dynasty|last imperial dynasty]] [[1911 Revolution|ended]] in 1912. The resulting [[Republic of China (1912–1949)|republic]] was replaced, after [[Chinese Civil War|another civil war]], by the communist [[China|People's Republic of China]] in 1949. At the end of the 20th century, though still ruled by a communist party, China's economic system had [[Chinese economic reform|largely transformed]] to [[capitalism]].
* [[Mahatma Gandhi]]'s [[nonviolence]] and [[Indian independence movement]] against the [[British Empire]] influenced many [[political movement]]s around the world, including the [[civil rights movement]] in the United States, and freedom movements in South Africa against [[apartheid]] challenging [[racial segregation]] 
* [[Decolonization|The end]] of [[colonialism]] led to the independence of many [[Decolonisation of Africa|African]] and [[Decolonisation of Asia|Asian]] countries. During the Cold War, many of these aligned with the United States, the USSR, or China for defense.
[[File:20091002 Hong Kong 6269.jpg|thumb|[[British Hong Kong|Hong Kong]], under British administration from 1842 to 1997, is one of the original [[Four Asian Tigers]].]]
* [[Mao Zedong]]'s [[Great Leap Forward|radical policy of modernization]] leads to the [[Great Chinese Famine]] causing the death of tens of millions of Chinese peasants between 1959 and 1962. It is thought to be the largest [[famine]] in [[human history]].<ref name="bmj.com">"[http://www.bmj.com/cgi/content/extract/319/7225/1619 China's great famine: 40 years later]". ''[[British Medical Journal]]'' 1999;319:1619–1621 (December 18 )</ref>
* The [[Vietnam War]] caused [[Vietnam War casualties|two million deaths]], changed the dynamics between the [[Eastern Bloc|Eastern]] and [[Western Bloc]]s, and altered global [[North–South divide in the World|North-South relations]].<ref>{{Cite journal|last=Thee|first=Marek|jstor=423343
|title=The Indochina Wars: Great Power Involvement – Escalation and Disengagement |journal=[[Journal of Peace Research]]|publisher=[[SAGE Publications]]|volume=13|issue=2|pages=117–129|year=1976|issn=1460-3578 |doi=10.1177/002234337601300204|s2cid=110243986}}</ref>
* The [[Soviet–Afghan War|Soviet invasion of Afghanistan]] caused million of deaths and contributed to the dissolution of the Soviet Union along with complete [[Afghanistan conflict (1978–present)|political turmoil]] in Afghanistan<ref name="bmj.com"/>
* The [[revolutions of 1989]] released Eastern and Central Europe from [[Soviet Empire|Soviet control]]. Soon thereafter, the [[Dissolution of the Soviet Union|Soviet Union]], [[Dissolution of Czechoslovakia|Czechoslovakia]], and [[Breakup of Yugoslavia|Yugoslavia]] dissolved; the former having many states seceded and the latter violently over several years, into [[successor state]]s, with many rife with [[ethnic nationalism]]. Meanwhile, [[East Germany]] and [[West Germany]] [[German reunification|were reunified in 1990]].
* The [[Tiananmen Square protests of 1989]], culminating in the deaths of hundreds of civilian protesters, were a series of demonstrations in and near Tiananmen Square in Beijing, China. Led mainly by students and intellectuals, the protests occurred in a year that saw the collapse of a number of communist governments around the world.
* [[European integration]] began in earnest in the 1950s, and eventually led to the [[European Union]], a political and economic union that comprised 15 countries at the end of the 20th century.