Korean War (1950–1953) 1950 North Korean Communist forces invade South Korea(June 25).UN calls for cease-fire and asks UN members to assist South Korea(June 27).Truman orders U.S. forces into Korea(June 27).North Koreans capture Seoul(June 28).Gen. Douglas MacArthur designated commander of unified UN forces(July 8).Pusan Beachhead—UN forces counterattack and capture Seoul(Aug.–Sept.),capture Pyongyang, North Korean capital(Oct.).Chinese Communists enter war(Oct. 26),force UN retreat toward 38th parallel(Dec.). 1951 Gen. Matthew B. Ridgway replaces MacArthur after he threatens Chinese with massive retaliation(April 11).Armistice negotiations(July)continue with interruptions untilJune 1953. 1953 Armistice signed(July 27).Chinese troops withdraw from North Korea(Oct. 26, 1958),but over 200 violations of armistice noted to1959.

Vietnam War U.S., South Vietnam, and Allies versus North Vietnam and National Liberation Front (Viet Cong). 1950 President Truman sends 35-man military advisory group to aid French fighting to maintain colonial power in Vietnam. 1954 After defeat of French at Dien Bien Phu, Geneva Agreements(July)provide for withdrawal of French and Vietminh to either side of demarcation zone (DMZ) pending reunification elections, which are never held. Presidents Eisenhower and Kennedy (from 1954onward) send civilian advisers and, later, military personnel to train South Vietnamese. 1960 Communists form National Liberation Front in South. 1960–1963 U.S. military advisers in South Vietnam rise from 900 to 15,000. 1963 Ngo Dinh Diem, South Vietnam's premier, slain in coup(Nov. 1). 1964 North Vietnamese torpedo boats reportedly attack U.S. destroyers in Gulf of Tonkin(Aug. 2).President Johnson orders retaliatory air strikes. Congress approves Gulf of Tonkin resolution(Aug. 7)authorizing president to take “all necessary measures” to win in Vietnam, allowing for the war's expansion. 1965 U.S. planes begin combat missions over South Vietnam. InJune,23,000 American advisers committed to combat. By end of year over 184,000 U.S. troops in area. 1966 B-52s bomb DMZ, reportedly used by North Vietnam for entry into South(July 31). 1967 South Vietnam National Assembly approves election of Nguyen Van Thieu as president(Oct. 21). 1968 U.S. has almost 525,000 men in Vietnam. In Tet offensive(Jan.–Feb.),Viet Cong guerrillas attack Saigon, Hue, and some provincial capitals. In My Lai massacre, American soldiers kill 300 Vietnamese villagers(March 16).President Johnson orders halt to U.S. bombardment of North Vietnam(Oct. 31).Saigon and N.L.F. join U.S. and North Vietnam in Paris peace talks. 1969 President Nixon announces Vietnam peace offer(May 14)—begins troop withdrawals(June).Viet Cong forms Provisional Revolutionary Government. U.S. Senate calls for curb on commitments(June 25).Ho Chi Minh, 79, North Vietnam president, dies(Sept. 3);collective leadership chosen. Some 6,000 U.S. troops pulled back from Thailand and 1,000 marines from Vietnam (announcedSept. 30). Massive demonstrations in U.S. protest or support war policies(Oct. 15). 1970 U.S. troops invade Cambodia in order to destroy North Vietnamese sanctuaries(May 1). 1971 Congress bars use of combat troops, but not air power, in Laos and Cambodia(Jan. 1).South Vietnamese troops, with U.S. air cover, fail in Laos thrust. Many American ground forces withdrawn from Vietnam combat.New York Timespublishes Pentagon papers, classified material on expansion of war(June). 1972 Nixon responds to North Vietnamese drive across DMZ by ordering mining of North Vietnam ports and heavy bombing of Hanoi-Haiphong area(April 1).Nixon orders “Christmas bombing” of North to get North Vietnamese back to conference table(Dec.). 1973 President orders halt to offensive operations in North Vietnam(Jan. 15).Representatives of North and South Vietnam, U.S., and N.L.F. sign peace pacts in Paris, ending longest war in U.S. history(Jan. 27).Last American troops departed in their entirety(March 29). 1974 Both sides accuse each other of frequent violations of cease-fire agreement. 1975 Full-scale warfare resumes. South Vietnam premier Nguyen Van Thieu resigns(April 21).South Vietnamese government surrenders to North Vietnam; U.S. Marine embassy guards and U.S. civilians and dependents evacuated(April 30).More than 140,000 Vietnamese refugees leave by air and sea, many to settle in U.S. Provisional Revolutionary Government takes control(June 6). 1976 Election of National Assembly paves way for reunification of North and South.

World War II (1939–1945) Axis powers (Germany, Italy, Japan, Hungary, Romania, Bulgaria)versusAllies (U.S., Britain, France, USSR, Australia, Belgium, Brazil, Canada, China, Denmark, Greece, Netherlands, New Zealand, Norway, Poland, South Africa, Yugoslavia). 1939 Germanyinvades Polandand annexes Danzig; Britainand Francegive Hitlerultimatum(Sept. 1),declare war(Sept. 3).Disabled German pocket battleshipAdmiral Graf Speeblown up off Montevideo, Uruguay, on Hitler's orders(Dec. 17).Limited activity (“Sitzkrieg”) on Western Front. 1940 Nazis invade Netherlands, Belgium, and Luxembourg(May 10). Chamberlainresigns as Britain's prime minister; Churchilltakes over(May 10).Germans cross French frontier(May 12)using air/tank/infantry “Blitzkrieg” tactics. Dunkerque evacuation> about 335,000 out of 400,000 Allied soldiers rescued from Belgium by British civilian and naval craft(May 26–June 3).Italy declares war on France and Britain; invades France(June 10).Germans enter Paris; city undefended(June 14).France and Germany sign armistice at Compiègne(June 22).Nazis bomb Coventry, England(Nov. 14). 1941 Germans launch attacks in Balkans. Yugoslavia surrenders—General Mihajlovic continues guerrilla warfare; Tito leads left-wing guerrillas(April 17).Nazi tanks enter Athens; remnants of British Army quit Greece(April 27).Hitler attacks Russia(June 22).Atlantic Charter—FDR and Churchill agree on war aims(Aug. 14).Japanese attacks on Pearl Harbor, Philippines, Guam force U.S. into war; U.S. Pacific fleet crippled(Dec. 7).U.S. and Britain declare war on Japan. Germany and Italy declare war on U.S.; Congress declares war on those countries(Dec. 11). 1942 British surrender Singapore to Japanese(Feb. 15).Roosevelt orders Japanese and Japanese Americans in western U.S. to be exiled to “relocation centers,” many for the remainder of the war(Feb. 19).U.S. forces on Bataan peninsula in Philippines surrender(April 9).U.S. and Filipino troops on Corregidor island in Manila Bay surrender to Japanese(May 6).Village of Lidice in Czechoslovakia razed by Nazis(June 10).U.S. and Britain land in French North Africa(Nov. 8). 1943 Casablanca Conference—Churchill and FDR agree on unconditional surrender goal(Jan. 14–24).German 6th Army surrenders at Stalingrad—turning point of war in Russia(Feb. 1–2).Remnants of Nazis trapped on Cape Bon, ending war in Africa(May 12).Mussolini deposed; Badoglio named premier(July 25).Allied troops land on Italian mainland after conquest of Sicily(Sept. 3).Italy surrenders(Sept. 8).Nazis seize Rome(Sept. 10).Cairo Conference: FDR, Churchill, Chiang Kai-shek pledge defeat of Japan, free Korea(Nov. 22–26).Tehran Conference: FDR, Churchill, Stalin agree on invasion plans(Nov. 28–Dec. 1). 1944 U.S. and British troops land at Anzio on west Italian coast and hold beachhead(Jan. 22).U.S. and British troops enter Rome(June 4).D-Day—Allies launch Normandy invasion(June 6).Hitler wounded in bomb plot(July 20).Paris liberated(Aug. 25).Athens freed by Allies(Oct. 13).Americans invade Philippines(Oct. 20).Germans launch counteroffensive in Belgium—Battle of the Bulge(Dec. 16). 1945 Yalta Agreement signed by FDR, Churchill, Stalin—establishes basis for occupation of Germany, returns to Soviet Union lands taken by Germany and Japan; USSR agrees to friendship pact with China(Feb. 11).Mussolini killed at Lake Como(April 28).Admiral Doenitz takes command in Germany; suicide of Hitler announced(May 1).Berlin falls(May 2).Germany signs unconditional surrender terms at Rheims(May 7).Allies declare V-E Day(May 8).Potsdam Conference—Truman, Churchill, Atlee (afterJuly 28), Stalin establish council of foreign ministers to prepare peace treaties; plan German postwar government and reparations(July 17–Aug. 2).A-bomb dropped on Hiroshima by U.S.(Aug. 6).USSR declares war on Japan(Aug. 8).Nagasaki hit by A-bomb(Aug. 9).Japan agrees to surrender(Aug. 14).V-J Day—Japanese sign surrender terms aboard battleshipMissouri(Sept. 2).

The Holocaust (1933–1945) “Holocaust” is the term describing the Nazi annihilation of about 6 million Jews (two thirds of the pre-World War II European Jewish population), including 4,500,000 from Russia, Poland, and the Baltic; 750,000 from Hungary and Romania; 290,000 from Germany and Austria; 105,000 from The Netherlands; 90,000 from France; 54,000 from Greece. The Holocaust was unique in its beinggenocide—the systematic destruction of a people solely because of religion, race, ethnicity, nationality, or sexual preference—on an unmatched scale. Along with the Jews, another 9 to 10 million people—Gypsies, Slavs (Poles, Ukrainians, and Belarussians), homosexuals, and the disabled—were exterminated. 1933 Hitler named German Chancellor(Jan.).Dachau, first concentration camp, established(March).Boycotts against Jews begin(April). 1935 Anti-Semitic Nuremberg Laws passed by Reichstag; Jews lose citizenship and civil rights(Sept.). 1937 Buchenwald concentration camp opens(July). 1938 Extension of anti-Semitic laws to Austria after annexation(March).Kristallnacht(Night of Broken Glass)—anti-Semitic riots and destruction of Jewish institutions in Germany and Austria(Nov. 9).26,000 Jews sent to concentration camps; Jewish children expelled from schools(Nov. 9–10).Expropriation of Jewish property and businesses(Dec.). 1940 As war continues, Einsatzgruppen (mobile killing squads) follow German army into conquered lands, rounding up and massacring Jews and other “undesirables.” 1941 Goering instructs Heydrich to carry out the “final solution to the Jewish question”(July 31).Deportation of German Jews begins; massacres of Jews in Odessa and Kiev(Nov.);and in Riga and Vilna(Dec.). 1942 Mass killings using Zyklon-B begin at Auschwitz-Birkenau(Jan.).Nazi leaders attend Wannsee Conference to coordinate the “final solution”(Jan. 20).100,000 Jews from Warsaw Ghetto deported to Treblinka death camp(July). 1943 Warsaw Ghetto uprisings(Jan.andApril);Ghetto exterminated(May). 1944 476,000 Hungarian Jews sent to Auschwitz(May–June).D-day(June 6).Soviet Army liberates Maidanek death camp(July).Nazis try to hide evidence of death camps(Nov.). 1945 As Allies advance, Nazis force concentration camp inmates on death marches. Americans liberate Buchenwald and British liberate Bergen-Belsen camps(April).Nuremberg War Crimes Trial(Nov. 1945–Oct. 1946).

World War I (1914–1918) Imperial, territorial, and economic rivalries led to the “Great War” between the Central Powers (Austria-Hungary, Germany, Bulgaria, and Turkey) and the Allies (U.S., Britain, France, Russia, Belgium, Serbia, Greece, Romania, Montenegro, Portugal, Italy, and Japan). About 10 million combatants killed, 20 million wounded. 1914 Austrian Archduke Francis Ferdinand and wife assassinated in Sarajevo by Serbian nationalist, Gavrilo Princip(June 28).Austria declares war on Serbia(July 28).Germany declares war on Russia(Aug. 1),on France(Aug. 3),invades Belgium(Aug. 4).Britain declares war on Germany(Aug. 4).Germans defeat Russians in Battle of Tannenberg on Eastern Front(Aug.).First Battle of the Marne(Sept.).German drive stopped 25 miles from Paris. By end of year, war on the Western Front is “positional” in the trenches. 1915 German submarine blockade of Great Britain begins(Feb.).Dardanelles Campaign—British land in Turkey(April),withdraw from Gallipoli(Dec.–Jan. 1916).Germans use gas at second Battle of Ypres(April–May).Lusitaniasunk by German submarine—1,198 lost, including 128 Americans(May 7).On Eastern Front, German and Austrian “great offensive” conquers all of Poland and Lithuania; Russians lose 1 million men (bySept. 6). “Great Fall Offensive” by Allies results in little change from 1914(Sept.–Oct.).Britain and France declare war on Bulgaria(Oct. 14). 1916 Battle of Verdun—Germans and French each lose about 350,000 men(Feb.).Extended submarine warfare begins(March).British-German sea battle of Jutland(May);British lose more ships, but German fleet never ventures forth again. On Eastern Front, the Brusilov offensive demoralizes Russians, costs them 1 million men(June–Sept.).Battle of the Somme—British lose over 400,000; French, 200,000; Germans, about 450,000; all with no strategic results(July–Nov.).Romania declares war on Austria-Hungary(Aug. 27).Bucharest captured(Dec.). 1917 U.S. declares war on Germany(April 6).Submarine warfare at peak(April).On Italian Front, Battle of Caporetto—Italians retreat, losing 600,000 prisoners and deserters(Oct.–Dec.).On Western Front, Battles of Arras, Champagne, Ypres (third battle), etc. First large British tank attack(Nov.).U.S. declares war on Austria-Hungary(Dec. 7).Armistice between new Russian Bolshevik government and Germans(Dec. 15). 1918 Great offensive by Germans(March–June).Americans' first important battle role at Château-Thierry—as they and French stop German advance(June).Second Battle of the Marne(July–Aug.)—start of Allied offensive at Amiens, St. Mihiel, etc. Battles of the Argonne and Ypres panic German leadership(Sept.–Oct.).British offensive in Palestine(Sept.).Germans ask for armistice(Oct. 4).British armistice with Turkey(Oct.).German Kaiser abdicates(Nov.).Hostilities cease on Western Front(Nov. 11).