Major Military Operations Since World War II

Updated July 31, 2023 | Infoplease Staff
Fighter jets
Source: Getty Images

The global spread of the First and Second World Wars made them the two most notable events of the 20th century. But they were far from the only major conflicts.

Large-scale military warfare has been happening for as long as humans have had access to weapons. Since the end of World War II in 1946, wars have continued to flare up across the globe and are increasingly shaped by technology.

Have There Been Any Wars Since WWII?

Since 1946, there have been no conflicts on the same scale as World War II but major conflicts have continued. Data collected by the Uppsala University in Sweden identifies 285 distinct armed conflicts having taken place since 1946.

The typical number of conflicts each year is between 30 and 50 with armed conflicts divided into three categories: "state-based", "non-state", and "one-sided" conflicts.

What Defines a Modern War?

What’s regarded as modern warfare is constantly evolving over time but it is generally associated with post-World War II conflicts with an increased focus on technology. Modern wars are increasingly reliant on tracking systems, drones, and AI-controlled vehicles with much less emphasis on the traditional "boots on the ground".

What Is the Difference Between a Modern War and a Traditional War?

Modern war is often referred to as "fourth-generation" warfare. This is a form of war in which conflicts are complex, long-term, and decentralized with a blurring of the lines between military and civil strategies. The difference with a traditional war is that military action tends to be an element of more diverse political, social, and economic battlegrounds.

Modern wars are fought as much over social media and various forms of political and social pressure as they are on battlefields. It’s the difference between the wars of attrition experienced during the two world wars with Germany and the more virtual form of media-led warfare that is seen in the ongoing Russo-Ukranian War. 

Conflicts after World War II

The major conflicts that followed World War I and World War II have mostly taken place outside of Europe. They have been shaped by the Cold War and an increasing shift to the middle east with tensions between armed groups over competing ethnic and religious affiliations.

World War II was the last war fought in which the President asked Congress for a declaration of war. However, since then, the United States armed forces have been in combat several times, including the following timeline of operations.


Korean War

With Japan’s defeat in World War II, the Korean lands are divided into two states— north and south. In 1950, Communist North Korea, supported by China, invades non-communist South Korea. UN forces, principally made up of U.S. troops, fight to protect South Korea. North Korea receives support from China and the Soviet Union.

It develops into a war of attrition on the ground while U.S. forces launch a major bombing campaign on North Korea. Lasting for three years, the number of deaths is estimated at around 170,000.

The Korean War is the first conflict in which air combat between jet-powered fighters takes place. It can also be considered the start of the Cold War with global alignments between communist states and western democracies.


Bay of Pigs

On April 17, an armed group of around 1,500 Cuban exiles attempt to invade Cuba and overthrow its Sovet-backed leader Fidel Castro. The plan is backed by the United States through the CIA with the hope that it will spark an uprising within Cuba to overthrow Castro and establish a non-communist state.

The invasion fails as more than 20,000 Cuban soldiers repel the insurgents as the forces clash along the Bay of Pigs on the south coast of Cuba. An estimated 118 of the invaders are killed and more than 1,200 are taken as prisoners.

The Bay of Pigs invasion is part of the escalating Cold War tensions between the US and the USSR and would play an influential role in the Cuban Missile Crisis of 1963.


Vietnam War    


In 1954, Vietnam breaks free from the colonial rule of France to become an independent republic. The following year, communist North Vietnam invades non-communist South Vietnam in an attempt to unify the country and impose the communist rule. The United States joins the war on the side of South Vietnam in 1961 but withdraws combat troops in 1973.

In 1975 North Vietnam succeeds in taking control of South Vietnam. The Vietnam War is the longest American war ever fought and the first war it lost. From 1964 onwards, around 2.2 million Americans were conscripted to fight in the war. Opposition to conscription and the war becomes a focal point for a hippie and counter-culture movement.


Dominican Republic

U.S. president Lyndon Johnson sends marines and troops to quash a leftist uprising; he fears the Dominican Republic might follow in the footsteps of Cuba and turn communist.



U.S. troops form part of a multinational peacekeeping force to help the fragile Lebanese government maintain power in the politically volatile country. In 1983 241 U.S. Marines and 60 French soldiers are killed by a truck bomb. The multinational force withdraws in 1984.

Falklands War

A military conflict between the United Kingdom and Argentina over the territorial rights to the Falklands Islands, known in Argentina as Islas Malvinas. Argentina claimed the islands, which have a population of around 4,000, were in their territory and challenged the legitimacy of the British controlling it as a Crown colony.

Leopoldo Galtieri, President of Argentina, sent a force to occupy the island with British Prime Minister Margaret Thatcher launching an immediate military response. A British task force of 127 warships was among the fleet to make the 8,000-mile journey across the South Atlantic.

The conflict lasted for 74 days with around 649 Argentinian lives lost and 255 British. Three Falklanders also died during the fighting. The Argentinian forces surrendered on June 14 and the British retook control of the islands.



U.S. President Ronald Reagan invades the Caribbean island nation of Grenada to overthrow its socialist government, which has close ties with Cuba. A U.S. peace-keeping force remains until 1985.



U.S. President George H. W. Bush invades Panama and overthrows Panamanian dictator and drug-smuggler Manuel Noriega. Noriega is later tried and convicted on a number of charges, and is imprisoned in the United States.


First Gulf War

The conflict starts when Iraq invades the country of Kuwait. In response, a 35-strong U.S.-led coalition of countries launches an attack on Iraq. The joint military response involved a two-phase plan with Operation Desert Shield building up forces and supplies and Operation Desert Storm to launch an aerial and naval bombardment of Iraqi troops in Kuwait.

The First Gulf War ends swiftly with Kuwait liberated. American-led forces initially began to advance toward Iraq but a ceasefire was declared before any attack commences. It’s estimated that around 50,000 Iraqi soldiers are killed with less than 300 coalition deaths.



A U.S.-led multinational force attempts to restore order to war-torn Somalia so that food can be delivered and distributed within the famine-stricken country.



After Haiti's democratically elected president Jean-Bertrand Aristide is ousted in a coup in 1991, a U.S. invasion three years later restores him to power.


Bosnian War    

The Bosnian War erupts after Bosnia and Herzegovina declares its independence from Yugoslavia. The new people’s republic creates a power struggle power between the various ethnic groups that exist within the region: Bosniaks, Serbs, Croats, and Yugoslavs.

It turns into a civil war with claims of ethnic cleansing such as the 8,000 reported deaths caused by a Bosnian Serb attack on the town of Srebrenica in July 1995. The war ends after a NATO bombing campaign on Bosnia forced Bosnian Serbs to the negotiating table with the Dayton Accords bringing a peace agreement.


Second Congo War

The deadliest conflict since World War II led to the deaths of an estimated 5.4 million people, mainly through disease and starvation. The conflict follows a year after the First Congo War large numbers of refugees, mainly Hutu, escaping into the Congo from neighboring Rwanda.

The ethnic tensions triggered by the Rwandan migration gave rise to the Second Congo War with eastern Congo becoming a war zone of rival groups and factions with an invasion by Rwandan and Ugandan joint forces.

Over the five years, nine neighboring countries are drawn into the war, including Angola, Namibia and Zimbabwe. The United Nations also sent 5,000 peacekeepers into the area in July 1999. The escalating nature of the conflict has led to it being referred to by some as the African World War.

Kosovo War    

Then-Yugoslavia's province of Kosovo erupts into war in the spring of 1999. Fighting breaks out between the forces of the Federal Republic of Yugoslavia and a rebel group known as the Kosovo Liberation Army (KLO).

The KLA was formed in protest against the Serbian treatment of Kosovo Albanians. In response to the group’s attacks, the Yugoslav authorities began to repress Kosovar Albanians with claims of ethnic cleansing made against Serbian president Slobodan Milošević.

The war ended with the Kumanovo Treaty signed on June 9 which saw Yugoslav and Serb forces agreeing to withdraw from Kosovo and allow NATO troops to enter. An estimated 1.2 million Kosova Albanians were displaced during the conflict.



The Taliban government harbored Osama bin Laden and the al-Qaeda terrorist group, responsible for Sept. 11, 2001, attacks on the United States. After Afghanistan refused to turn over Bin Laden, the U.S. and UN coalition forces invaded. The Taliban government was ousted and many terrorist camps in Afghanistan were destroyed. Thereafter, the Taliban begin regrouping. By 2005, the Taliban and coalition troops are engaged in ongoing clashes with coalition troops. The year 2006 was the deadliest year of the war in Afghanistan for American soldiers since 2001.

On May 2, 2011 (May 1 in the U.S.), U.S. troops and CIA operatives shot and killed Osama bin Laden in Abbottabad, Pakistan.

On May 1, 2012, President Obama and President Karzai signed the Enduring Strategic Partnership Agreement between the Islamic Republic of Afghanistan and the United States of America. The Agreement provides for the possibility of U.S. forces in Afghanistan after 2014, for the purposes of training Afghan Forces and targeting the remnants of al-Qaeda. Afghanistan will be a Major Non-NATO Ally and as such, the U.S. will support the training, equipping, advising, and sustaining of Afghan National Security Forces, and social and economic assistance.

The United States completed the withdrawal of troops from Afghanistan on August 30, 2021, marking an end to the conflict. Following the withdrawal, Taliban forces took control of the country with the intention to create an "open, inclusive Islamic government".



Second Gulf War    

The U.S. military and Great Britain lead a coalition of countries that invade Iraq and topple the government of dictator Saddam Hussein. The invasion is based on claims that Iraq has "weapons of mass destruction", despite an inspection team from the United Nations having found no evidence.

The lack of "weapons of mass destruction" found after the invasion raises concerns about the legitimacy of the Iraq War. The operations in Iraq continue for several years as the country experiences escalating violence and fragile political stability.

On Aug. 31, 2010, President Obama announces the end of U.S. army combat missions in Iraq. Effective September 1, 2010, the military operations in Iraq acquired a new official designation: “Operation New Dawn" with a commitment to developing the areas of defense and security; education and culture; energy; human rights; services; and trade.

War in Darfur

Sometimes known as the Land Cruiser War, this is a major conflict that broke out in the Darfur region of western Sudan. It was triggered by two rebel groups, the Sudan Liberation Movement (SLM) and the Justice and Equality Movement (JEM), launching attacks against the Sudan government.

The rebel groups accused the government of ignoring the western region and its predominantly non-Arab population. In response, the Sudanese government supported Arab militia groups that become known as Janjaweed.

It creates a warzone with fighting between the groups that results in hundreds of thousands dead with claims of ethnic cleansing and genocide. It’s estimated that around two million have migrated to escape from the conflict.



In early 2011, a coalition of nineteen states began intervening in the civil infighting in Libya. By March, NATO officially took control of the situation and assisted rebel forces against the government of Muammar Gaddafi. The intervention lasted until November when fighting dropped off following Gaddafi's death.


War with ISIL    

In 2012 militants in Iraq and Syria declared a new caliphate and rapidly seized a large territory. They began a widespread propaganda campaign to cultivate domestic terrorism in other countries and to recruit new members. The United States and other NATO allies began a long campaign to contain and reverse the spread of ISIL.

By 2018, ISIL no longer held any territory in Iraq, and severely declined in Syria. The United States continued airstrikes against the Assad regime as well as against the remaining ISIL holdouts. These airstrikes, by March 2019, contributed to ISIL losing all of its remaining territory. In October 2019 a US airstrike caused the death of ISIL leader Abu Bakr al-Baghdadi.


2014- Present


The Syrian civil war is an ongoing conflict with groups opposed to the Syrian Arab Republic led by president Bashar al-Assad. Many of the early insurgency protests originate in the southern region that is associated with the country’s Sunni population.

The civil war has taken on a global dimension with nations allying with the Syrian government or with the rebel groups seeking to overthrow them. The United States has been among a coalition of western democracies to support the rebel groups while Russia and Turkey have aligned with the Syrian government.

Events escalated in 2017 when the United States launched a missile attack on the Shayrat Airbase in retaliation for a chemical attack the U.S. accused the Syrian government of carrying out in Khan Shaykhun.


Russo-Ukrainian War

The Russo-Ukranian War follows the Ukrainian Revolution that takes place on February 2014 with the Ukrainian government of Viktor Yanukovych overthrown. When Russia calls the coup illegal and refuses to recognize the legitimacy of the interim government, the Russo-Ukrainian War is triggered.

The conflict started with clashes between groups of pro-Russian separatists in the eastern Donbas region taking control of government buildings and declaring breakaway states in Donetsk and Luhansk.

Russia provides support to the pro-Russian separatists who are fighting the Ukrainian forces. As the situation escalates, Russian troops invade the Donbas area and with Donetsk, Luhansk, and Mariupol being major areas of conflict.

The situation escalates in February 2022 when Russian mounts a full invasion with the aim to "demilitarize and denazify" Ukraine. The invasion provoked a large international response with the United Nations demanding the withdrawal of Russian troops.

After WW2: Modern Warfare

As modern warfare evolves in the 21st century, the difficulties of defining what is and isn’t a war will continue to grow. The complexity and decentralized nature of modern conflicts make conflicts multi-faceted and with military action just a part of the armory of modern warfare.

Traditional forms of warfare with two armed forces clashing at a battleground may soon become a part of military history as remote technology removes the need for "boots on the ground". To chart how the nature of war is changing, you can find a comprehensive list of global wars and battles. Or, test your knowledge with our History of Modern War quiz.

Return to Top of Page

Sources +