Home > Glossary

Conflict Descriptions

World War I

On 28 June 1914, in Sarajevo, a Serb nationalist assassinated Archduke Franz Ferdinand, heir to the Austro-Hungarian throne. Due to a network of competing alliances, a European history of nationalistic rivalry over colonies and military dominance, and the importance of being the first to mobilize reserve forces for war, this small event initiated what was then the largest conflict the world had ever experienced. The Austro-Hungarians, allied with Germany, made demands on Serbia, backed by Russia, which was in turn allied with France. Great Britain supported Russia and France in what was known as the Triple Entente. In the event of war with Russia and France, the German Schlieffen Plan envisioned a quick victory over France, which necessitated violation of the neutrality of Belgium, so that it could then turn all its attention to Russia, which would mobilize much more slowly. Within one week of Austro-Hungary's 28 July declaration of war on Serbia, most of Europe was embroiled. Japan, an ally of Great Britain, joined in on 23 August, thus extending the conflict to the Pacific. The Ottoman Empire also would come in on the side of Germany and extend the war into the Middle East, while Italy would side with Triple Entente in 1915. By the time the Great War (as it was known prior to World War II) ended in 1918, more than nine million soldiers and a further five million civilians had died. The initial German advance through Belgium and into France was successful, but ultimately ran out of steam short of Paris in the face of stiffening French and British resistance. As each side tried to outflank the other, a series of opposing defensive trenches soon stretched from the English Channel to Switzerland. Coupled with machine guns, barbed wire, and modern artillery, the fortified lines led to a static battle of attrition on this front. The introduction of chemical weapons and the tank brought short-term advantages but no significant change in the front lines. The battle lines were not as static in the East, but neither side could gain the upper hand over the other. The year 1917 saw great changes in the war. Cumulative French manpower losses and mutinies brought its military to the brink of collapse. Similar war weariness contributed to Czar Nicolas' abdication and Russian withdrawal from the conflict. But the German use of unrestricted submarine warfare, which resulted in the death of U.S. citizens on the high seas, brought the United States into the war on 6 April. The subsequent injection of the American Expeditionary force and its two million soldiers offset Germany's ability to focus all its forces on the western front in 1918. A series of German offensives in early 1918 brought the first major gains of territory in the west since 1914, but Allied ripostes regained much of the ground and drove Germany back toward its own borders as the year progressed. By October, the Austro-Hungarian Empire had disintegrated and the Ottoman Empire had surrendered. On 11 November 1918, Germany agreed to a ceasefire. With the signing of the Treaty of Versailles on 28 June 1919 the "war to end all wars" formally ended.


World War II

World War II was the largest and most violent military conflict in human history. Official casualty sources estimate battle deaths at nearly 15 million military personnel and civilian deaths at over 38 million. Fought largely between two opposing military alliances, the Allies and the Axis, the war engulfed Europe, North Africa, much of Asia and the world's oceans. Germany, Japan, and Italy led the loosely cooperating Axis nations. The major Allies were the United States, Great Britain, and the Soviet Union, although a great many other nations committed forces. The worldwide struggle officially began with the German attack on Poland on September 1, 1939, followed quickly by Great Britain, its Commonwealth dominions, and France declaring war on Germany. With the defeat of France in 1940, Great Britain fought off a German air campaign and escaped invasion. The German invasion of the Soviet Union in June 1941 brought that nation into the war and opened a major new theater. In Asia, the Japanese had been fighting to take over China since 1931. A surprise Japanese attack on the American fleet at Pearl Harbor in Hawaii in December 1941 brought the United States into the war on the side of the Allies and opened a 45-month struggle in the Pacific and Indian Oceans and Asia. The American and British-led invasions of North Africa and then Italy, along with Soviet successes, turned the tide against the Axis in Europe. The Allied landings in Normandy in June 1944 opened a western front and, coupled with continued Soviet offensives in the east, brought about the eventual defeat and unconditional surrender of Germany in May 1945. The war culminated with the United States dropping atomic bombs on two Japanese cities and the unconditional surrender of Japan on 2 September 1945.


Korean War

The Korean War began on June 25, 1950, when North Korea (officially the Democratic People's Republic of Korea) launched a surprise attack on neighboring South Korea (officially the Republic of Korea). Against the expectations of the North Koreans and the Soviet Union, the United States immediately provided military support to South Korea, and the UN Security Council passed a resolution (UNSC Resolution 82) demanding a North Korean withdrawal to the 38th Parallel. Within days of the initial assault, UN forces under the leadership of General Douglas MacArthur began planning a large-scale counterassault, culminating in the Battle of Inchon in September 1950. In the months following the invasion at Inchon, UN troops forced the North Korean Army to retreat, capturing the capital of Pyongyang and reaching North Korea's northernmost border at the Yalu River. With secret backing from Moscow, in October and November 1950 hundreds of thousands of Chinese troops moved into North Korea and forced the South Korean and UN troops to retreat. By the summer of 1951, the conflict on the ground stalemated. While aerial bombing of North Korea and localized battles and skirmishes continued, the two sides exchanged little territory over the next two years. The conflict ended with the signing of an armistice on July 27, 1953. It preserved the prewar geographic division of Korea, keeping North Korean and South Korean troops on active alert on opposite sides of the Military Demarcation Line.


Vietnam War

After eight years of warfare between the French and the communist-led Viet Minh, the 1954 Geneva Agreements ended France's colonial rule and partitioned Vietnam into a communist-controlled North and a non-communist South backed by the United States. In the South, beginning in 1957, communist Viet Cong waged a guerrilla campaign against the regime of Ngo Dinh Diem and drew increasing support from the North. The United States tried to bolster Diem's government with increasing numbers of advisers and material aid. In 1963, as the insurgency appeared to gain strength, South Vietnamese military officers overthrew Diem but the situation only worsened. In August 1964, following a North Vietnamese naval attack on a U.S. warship, the U.S. Congress approved the Tonkin Gulf Resolution (P.L. 88-408), authorizing President Johnson to expand conventional military operations in Vietnam without a formal declaration of war. During 1965, to prevent the imminent collapse of South Vietnam, the United States launched Rolling Thunder, a systematic bombing campaign against the North, and started committing ground combat forces in the South. The purpose of Rolling Thunder, never achieved, was to compel the North to stop helping the Viet Cong. By April 1969, despite U.S. military personnel in the South peaking at 543,400, victory remained elusive and more of the American public began to turn against the war. Rolling Thunder was suspended and in 1969 U.S. troop withdrawals began. Between 1970 and 1972, bombing of the North resumed intermittently and sometimes intensively but ground redeployments continued and the bulk of U.S. forces left the South. The Paris Peace Accords, signed on January 27, 1973, proved to be a temporary truce rather than a genuine peace. In the wake of North Vietnam's multiple assaults, South Vietnam collapsed in the spring of 1975. As North Vietnam took over, President Gerald R. Ford declared the Vietnam War over.


Persian Gulf War

The Persian Gulf War began on August 2, 1990, when approximately 100,000 Iraqi Army troops crossed the Kuwaiti border. The United Nations Security Council swiftly condemned Iraq, passing Resolution 660 demanding an immediate and unconditional withdrawal of Iraqi forces from Kuwait. After consulting with Saudi King Fahd, on August 6, 1990, President George H.W. Bush ordered the deployment of U.S. ground, air, and naval forces to the Arabian Peninsula. Named DESERT SHIELD, the initial phases of operations focused on deterring an invasion of Saudi Arabia and preparing to liberate Kuwait. Saddam Hussein's failure to comply with UN Security Council Resolution 678 of November 1990, which set January 15, 1991, as the deadline for Iraqi withdrawal from Kuwait, provided the impetus for the next phase of the campaign. The offensive war, Operation DESERT STORM, began on January 17, 1991, with air operations against Iraqi forces in Kuwait and selected targets inside Iraq. On February 28, 1991, a mere 100 hours after the coalition launched its ground offensive, U.S. Central Command liberated Kuwait and halted offensive operations. With the approval of the UN Security Council, a formal cease-fire took effect on April 11, thus ending the Persian Gulf War.


Global War on Terrorism

In response to the September 2001 terrorist attacks on New York's World Trade Center and the Pentagon, President George W. Bush launched the Global War on Terrorism (GWOT). As it evolved, his objective was two-fold: to destroy al Qaeda, the Taliban, and other terrorist groups in Afghanistan and around the world, and to remove Saddam Hussein from power to forestall threats from his presumed possession of weapons of mass destruction. Operation ENDURING FREEDOM began on October 7, 2001, when the United States launched military operations in Afghanistan, including airstrikes against Kabul and Kandahar. In sustaining military operations for over a decade, American troops continue to fight a widespread insurgency and establish a viable government. On May 1, 2011, US Navy SEALS killed al Qaeda leader Osama bin Laden in Pakistan. Simultaneous to the war in Afghanistan, the United States and its allies threatened military action if Iraq did not abide by all of the numerous UN resolutions of the past ten years, including UN Security Council Resolution 1441 (2002), which called on Iraq to cooperate unconditionally with UN weapons inspectors to verify that Iraq was not in possession of WMD and ballistic missiles. The United Nations Monitoring, Verification, and Inspection Commission (UNMOVIC) found no evidence of WMD, but could not verify the accuracy of Iraq's weapons declarations. In the face of Iraq's resistance to open inspections, U.S. and coalition forces on March 20, 2003, launched Operation IRAQI FREEDOM, a combined air and ground assault. U.S. troops seized Baghdad after just twenty-one days. A broad insurgency that ebbed and flowed over the next seven years challenged efforts to create a democratic Iraqi government and threatened open sectarian warfare between minority Sunni and majority Shia, with northern Kurds aspiring to regional autonomy amid the unrest. In January 2007, U.S. military forces implemented "the surge", a counterinsurgency strategy devised by General David Petraeus. U.S. combat operations ended on September 1, 2010. American troops remained in the country to advise Iraqi security forces as part of Operation NEW DAWN until the final withdrawal on December 15, 2011.