Top 10 Deadliest Wars Of The 20th Century

The 20th century was a period of conflicts and wars that shifted the power balance. This period also saw wars, in which the entire world was encompassed, and militaries used all available means and modes to win. Motives for these conflicts and wars ranged from the murder of populists to expansion disputes, etc. One thing common among all these wars was the huge number of casualties—not just soldiers but also civilians dying. Here’s a peek into the Top 10 Deadliest Wars Of The 20th Century, curated by the Top 10s Only team.

List Of The Top 10 Deadliest Wars Of The Twentieth Century 

Wars, no matter the magnitude, have a lasting impact on people. In the twentieth century, some wars altered history completely. In this article, we endeavour to look at the most gruesome wars that took place in the 20th century. 

1. Mexican Revolution (1910 – 1920)

The Mexican Revolution was one of the ten deadliest wars in history, that serve as a reminder of the loss that such wars bring. It was a complex and fierce conflict that spanned more than a decade and reshaped the social, economic and political status of Mexico. The Revolution started on the 20th of November, 1910, as a protest by the middle class against the long-standing President Porfirio Diaz, who was a dictator and had no succession plan. Francisco Madero removed Diaz; however, he was a weak leader who failed to implement the promised reforms. There was chaos and mess until Venustianio Carranza took over, formed a new constitution and an army, and accepted many of the demands of rebels. Carranza, who emerged as a leader, was, however, killed in 1920, marking the end of the revolution. About 1 to 2 million people sacrificed their lives for this revolution, but their efforts were not in vain as the country saw diminished foreign influence, peasant land rights were expanded, and nationalism was strengthened. 

2. World War One (1914 – 1918) 

Let’s now look at one of the largest wars of the 20th century. World War One is called the Great War and was a worldwide conflict between the Allies (France, Britain and Russia) and the Central Powers (Germany, Austria, Hungary, etc.). The triggers for this war were the assassination of Austria’s Archduke Franz Ferdinand, the shift in the power balance in Europe, and increased competition among nations due to imperialism and industrialisation. Initiated in 1914, it developed into a deadly conflict that ended on 11 November 1918 and spread from Europe to the United States, Russia, the Middle East, Asia, Turkey and Africa. The war was catastrophic, with a massive death toll, with estimates suggesting over 10 million deaths of military and civilian casualties. Unofficial estimates count it to be more than 20 million deaths. There was also a wide economic impact on the warring countries as well as major political consequences.  

3. Russian Civil War (1917-22)

The Russian Civil War in 1917 was one of the most explosive political wars in the 20th century. The civil war ended Russian imperial rule and also the Romanov dynasty. The reasons for the war were food shortages, economic hardships and corruption, which led to disillusionment among people with Czar Nicholas II after World War I. During the civil war, the Marxist Russian Social Democratic Labour Party faction led by Vladimir Lenin destroyed the Czar’s rule and seized power. The outcome of this civil war was the formation of the Soviet Union and more than 10 million people lost their lives in the process. This is why the Russian War is still considered one of the top deadliest wars in history.

4. World War Two (1939-45)

WW 2 had some of the most deadliest battles in history. It was a conflict between the Allies and the Axis and almost all the countries participated in this war. The unresolved tensions of World War I, militarism, and fascism were some of the reasons for this deadly war, which resulted in 70 to 85 million deaths, half of which were civilians. The war started in 1939 when Germany invaded Poland and the UK and France declared war on Germany. Soon other countries joined and escalated into a catastrophic war, which ended in 1945 after Germany surrendered and Japan was bombed. The war ended in 1945 with Germany’s surrender and Japan’s atomic bombings. WW II changed the social and political structure of the world and set the tone for international relations for the rest of the century and the 21st century. The United Nations was established to prevent conflicts and foster international cooperation. The USA and Soviet Union became rivals and the Cold War started. Europe’s power weaned and Africa and Asia got decolonised. 

5. Chinese Civil War (1945-49)

The Chinese Civil War was waged for control of China between the Communists and the Nationalists. During the Second Sino-Japanese War, China was divided into three regions: Nationalist China, Communist China and areas held by Japan. By the end of World War II, China had endured many decades of Japanese incursion and brutal warfare. Japan’s defeat triggered a conflict between the Nationalists and communists for control over population centres and vital resources. The struggle concluded in 1949 with the communists defeating the nationalists and forming the People’s Republic of China in 1949. The cost of this war was 1.5 million wounded and dead and about 5 million civilians died due to disease, famine and war. 

6. Korean War (1950-53)

The Korean War was a conflict between North Korea and South Korea. It started on the 25th of June, 1950 and ended on the 27th, of July, 1953, with the signing of an armistice that brought an end to the war.  At the end of World War II, Korea was divided with an internal border based on latitude along the 38th parallel. After a few years of tension between the two countries, the North Korean People’s Army invaded South Korea armed with tankers from Russia and support from China. The United States came to South Korea’s rescue and in the end an armistice was signed where it was agreed that Korea remains a divided country.  The Korean War was a three-year conflict with more than 3 million deaths and thousands injured. 

7. Vietnam War (1959 – 1975)

The Vietnam War is truly one of the biggest wars of the 20th century that has had a lasting impact on the people of two continents – North America and Asia. The Vietnam War is also called the Second Indochina War and also the American War in Vietnam. Officially, the war was a prolonged fight between North and South Vietnam but both were backed by other countries. North Vietnam was supported by China, the Soviet Union and the Eastern Bloc countries and South Vietnam by the United States and other anti-communist countries. This war, which lasted for more than two decades, was an attempt to stop the spread of communism. Despite those efforts, the conflict spread to Cambodia and Laos, with all three countries becoming communists in 1975. The cost of the war was the death of more than 3 million people, including more than 50,000 Americans. The war divided Americans and finally, President Nixon signed the Paris Peace Accord and withdrew US forces in 1973. Communists seized control, and the country became the Socialist Republic of Vietnam in 1976. 

8. Bangladesh Liberation War (26 March 1971 – 16 December 1971)

The Bangladesh Liberation War, also called the Bangladesh War of Independence, was a short conflict between the West and East of Pakistan. This armed conflict triggered the rise of the Bengali Nationalist movement and resulted in Bangladesh becoming independent. The war started when Pakistan launched Operation Searchlight against East Pakistan on 25 March 1971, which resulted in genocide. In response to this, the civilians and Bengali military launched a guerilla war against the Pakistani military. India too got involved and helped Bangladesh fight with Pakistan surrendering in Dhaka on December 16th, 1971. It is one of the largest surrenders of military personnel since World War II.

9. Iran-Iraq War (1980 – 1988)

The Iran-Iraq war is known as the First Gulf War and started in 1980 when Iraq launched an invasion of Iran. Tensions between the two countries date back to 1921 and the conflict was about who should control Shatt Al-Arab, a waterway formed by the Euphrates and Tigris river confluence. In 1975, Iraqi control over it was reduced by the Algiers agreement in exchange for the withdrawal of the Kurdish insurgency by Iran. Iraq was waiting for a chance to wrestle it back and the opportunity came when Iran’s government was destabilised due to the Iranian revolution. Iraq’s then-president Saddam Hussain launched an invasion, with Iran fighting back. After eight years of full-fledged war and destruction, a cease-fire was declared in 1988. The casualties were huge on both sides, with about 5,00,00 people dying. Apart from the death toll, the Gulf War hit oil supplies across the globe with an increase in oil prices. There was also significant social, political and cultural change in the Middle East and among those directly involved in the conflict.

10. Gulf War (1990 – 1991)

The Gulf War was fought by Iraq and a coalition of 42 countries led by the USA. The war was fought in two phases: Operation Desert Shield, where between August 1990 and January 1991, the military was gathered. Operation Desert Storm began with the aerial bombing of Iraq to liberate Kuwait on February 28, 1991. The cause of the war was an invasion of Kuwait by Iraq over a dispute regarding slant drilling and also the cancellation of debt to Kuwait from the Iran-Iraq war. The invasion was condemned and when Iraq did not give up control of Kuwait, it led to a war with an estimated death toll for Iraqis between 142,500 and 206,000. As a result of this war, Saddam Hussein, the mastermind behind both the Gulf Wars, was overthrown, and a new Iraqi government was formed. 

Impact Of The Major Wars And Conflicts Of The 20th Century

The 20th century was marked by some of the deadliest wars in history and resulted in the loss of human lives and properties, suffering, political upheavals and more. But not all wars resulted in gloom. Wars like the Gulf War, Vietnam War, and World War I & II reshaped the political landscape and had a lasting impact on international relations and global politics, while other wars like the Korean War, the Mexican Revolution, and the Bangladesh Liberation War shaped the nations.