Significant U.S. Conflicts

Updated July 22, 2020 | Infoplease Staff
 

During the first phase of its history, the United States tried to isolate itself from foreign conflicts. In the 1900s, however, the United States participated in two world wars, became a global superpower, and eventually became a major proponent of world trade.

1898

The United States wins the Spanish-American War and acquires foreign territoriesPuerto Rico, Guam, and The Philippines.

1914

World War I begins.

1917

The U.S. abandons neutrality to join the Allies in world War I.

1918

World War I ends.

1920

The Senate rejects the Treaty of Versailles and American membership in the League of Nations.

1921

The U.S. declares the war with Germany to be at and end.

1939

Germany invades Poland and World War II begins.

1941

Japanese forces assail Pearl Harbor. The U.S. declares war on the Axis Powers and enters World War II.

1945

End of World War II. The U.S. is a founding member of the United Nations.

1947

The end of World War II marks the beginning of the Cold War. Fearing the spread of Communism in war-torn Western Europe, the United States inaugurates the Marshall Plan.

1949

The U.S. and 11 other nations sign the North Atlantic Treaty, forming NATO.

1950

Communist North Korea invades South Korea. President Truman sends American troops to defend South Korea. The U.S. goes on to lead forces from 15 other nations in the Korean War (1950–1953).

1964

The U.S. Senate passes the Gulf of Tonkin Resolution at the request of President Johnson. The Resolution approves U.S. military involvement in the Vietnam conflict.

1973

President Nixon orders a halt to offensive operations in North Vietnam on Jan. 15 and representatives from all sides sign a peace pact, ending the longest war in U.S. history. The last American troops depart by March 1973.

1983

President Reagan orders an invasion of Grenada to establish order on the island and eliminate the Cuban military presence there. A U.S. peace-keeping force remains until 1985.

1989

The Berlin Wall comes down, marking the end of the Cold War.

1989

President Bush sends troops to Panama to depose and capture Manuel Noriega, who had been indicted for drug trafficking.

1991

Persian Gulf War—the U.S. leads a coalition of 32 countries to drive Iraq out of Kuwait, which it had invaded.

1993

U.S., Canada, and Mexico ratify the NAFTA free-trade agreement.

1993 Somalia

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.

1994 Haiti

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.

1994–1995 Bosnia

During the Bosnian civil war, which begins shortly after the country declares independence in 1992, the U.S. launches air strikes on Bosnia to prevent ethnic cleansing. It becomes a part of NATO's peacekeeping force in the region.

1995

The U.S. is a founding member of the World Trade Organization (WTO), formed to monitor and promote world trade.

1999 Kosovo

Yugoslavia's province of Kosovo erupts in war in the spring of 1999. A U.S.-led NATO force intervenes with air strikes after Slobodan Milosevic's Serbian forces uproot the population and embark on a plan of ethnic cleansing of Kosovo's ethnic Albanian population.

2001

After the September 11, 2001, terrorist attacks, the U.S. declares war on terrorism.

2001

Operation Enduring Freedom—the U.S. invades Afghanistan and deposes the Taliban, who had sheltered terrorist leader Osama bin Laden.

2003

The U.S. launches Operation Iraqi Freedom, an invasion of Iraq, as part of the war on terrorism.

2010

On Aug. 31, President Obama announces the end of U.S. combat missions in Iraq.

2010

Operation New Dawn begins on Sep. 1. A U.S. transitional troop force will remain in Iraq, tasked with the mission: "advising and assisting Iraq's Security Forces, supporting Iraqi troops in targeted counterterrorism missions, and protecting our civilians."

2011

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.

2012

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.

Reacting to instability due to Syria's civil war, the U.S. sends troops to neighboring Jordan--to contain the border; and Turkey--to prevent any Syrian-based missile strikes.

2014–present

According to the Department of Defense, 6,097 targets were damaged or destroyed as of April 23, 2015. The strikes were conducted as part of Operation Inherent Resolve, an undertaking meant to eliminate the Islamic State of Irag and the Levant (ISIL) terrorist group and the threat they pose to Iraq, Syria, the region, and the wider international community. Coalition nations conducting airstrikes in Iraq include the United States, Australia, Belgium, Canada, Denmark, France, Jordan, the Netherlands and the United Kingdom; coalition nations conducting airstrikes in Syria include the United States, Bahrain, Canada, Jordan, Saudi Arabia and the United Arab Emirates.

By 2018, ISIL no longer held any territory in Iraq, and severely declined in Syria. However, the United States continued airstrikes against the Assad regime. 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. The U.S. then performed a controversial withdrawal from Northern Syria ahead of a Turkish advance against the region's (U.S.-aligned) Kurdish militants. American forces have since entrenched themselves in Eastern Syria, and per military officials there is no clear end date to the U.S. intervention in Syria.

 
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