June 27 – July 7, 1991 · Slovenia Theater

When Slovenia declared independence on June 25, 1991, the Yugoslav People's Army (JNA) moved to seize border crossings and Ljubljana airport within hours. The Slovenian Territorial Defence, outnumbered but fighting on home ground, ambushed JNA columns, blocked fuel supplies, and surrounded isolated armored units in an asymmetric campaign that stunned the federal military. Within ten days the JNA had suffered an embarrassing stalemate — its tanks surrounded by farmers and militia in a republic that had no Serb minority to protect. The Brioni Declaration on July 7 halted fighting; the JNA withdrew from Slovenia within three months, and the war effectively ended.

August 25 – November 18, 1991 · Eastern Slavonia Theater

For 87 days, the baroque Danubian city of Vukovar endured the most sustained siege in Europe since World War II. Outnumbered Croatian defenders — many of them police officers and volunteers — held off tens of thousands of JNA troops and Serb paramilitary fighters, fighting street by street through a city reduced to rubble. The JNA expended more artillery ammunition on Vukovar than in any operation since the Second World War. When the city finally fell on November 18, Croatian defenders were promised safe passage; instead, hospital patients and wounded soldiers were taken to Ovčara farm on the city's outskirts and executed. The city was ethnically cleansed of nearly all its Croatian and other non-Serb residents.

October 1991 – May 1992 · Dalmatia Theater

In October 1991, JNA and Montenegrin forces surrounded the walled city of Dubrovnik — a UNESCO World Heritage Site — and began shelling one of the most architecturally intact medieval cities in Europe. The attack had no serious military objective; Dubrovnik had almost no Croatian military presence. The bombardment was intended to force Croatia into negotiations by threatening a city of immense cultural significance. International outrage was immediate and intense. Croatian defenders gradually pushed back the besieging forces through 1992, and the JNA's naval blockade was eventually lifted.

April 5, 1992 – February 29, 1996 · Central Bosnia Theater

Beginning April 5, 1992, Bosnian Serb forces under General Ratko Mladić ringed Sarajevo with artillery and sniper positions in the surrounding hills, beginning the longest siege of a capital city in the history of modern warfare — 1,425 days. An estimated 13,952 people were killed, including 5,434 civilians. Residents faced daily sniper fire on the 800-meter 'Sniper Alley,' artillery barrages targeting markets and breadlines, and years of severe shortages of food, water, electricity, and medicine during Balkan winters. The city survived through a UN airlift — the longest humanitarian airlift in history — and a tunnel dug under the airport that kept a lifeline open to the outside world. NATO air strikes following the February 1994 Markale marketplace massacre finally forced a partial withdrawal of heavy weapons.

July 11 – 22, 1995 · Eastern Bosnia Theater

On July 11, 1995, Bosnian Serb Army forces under General Ratko Mladić overran the UN-declared 'safe area' of Srebrenica, protected by a Dutch UNPROFOR battalion that numbered roughly 400 lightly armed soldiers. Mladić appeared before cameras promising the women and children they would be safe. Over the next seven days, his forces separated approximately 8,000 Bosniak men and boys from the refugee columns seeking safety at a nearby UN base, transported them to sites across eastern Bosnia, and executed them in the worst act of genocide in Europe since the Nazi Holocaust. The Dutch UN soldiers were powerless — or unwilling — to intervene. The victims' bodies were buried in mass graves, then exhumed and moved to secondary and tertiary graves in an attempt to hide the evidence.

August 4 – 7, 1995 · Krajina, Croatia Theater

Operation Storm was the largest European land offensive since World War II — a 200,000-strong Croatian military assault on the self-declared Republic of Serbian Krajina that retook the entire enclave in just 84 hours. The Croatian army, trained and equipped with US assistance, shattered Serbian defenses with coordinated artillery, infantry, and special forces operations across a 630-kilometer front. Knin, the Krajina's capital, fell within hours of the assault's opening. The collapse was so complete that the Serbian government in Belgrade, distracted by its own negotiations, abandoned the Krajina Serbs entirely. The military victory was total; the humanitarian aftermath was contested — an estimated 200,000 Serb civilians fled or were expelled, and hundreds of elderly Serbs who remained were killed in the weeks after the operation.

August 30 – September 20, 1995 · Bosnia-Herzegovina Theater

On August 28, 1995, a Bosnian Serb mortar shell killed 43 civilians at the Markale marketplace in Sarajevo — the second such massacre in eighteen months. NATO responded with its first sustained combat operation in its 46-year history: Operation Deliberate Force. Over 21 days, 400 aircraft from 15 nations flew 3,515 sorties and struck 338 Bosnian Serb military targets — ammunition depots, command centers, radar sites, and artillery positions ringing Sarajevo. The campaign was designed not to destroy Serbian forces but to coerce them: by demonstrating that NATO could strike at will, it stripped Karadžić and Mladić of their military leverage at a decisive political moment. Combined with Operation Storm's crushing defeat of Serb forces in Croatia, the air campaign broke the Bosnian Serbs' will to continue the war.

November 21, 1995 · Diplomacy Theater

After 21 days of intensive negotiations at Wright-Patterson Air Force Base in Dayton, Ohio, the presidents of Bosnia, Croatia, and Serbia initialed a peace agreement on November 21, 1995 that ended the Bosnian War. US envoy Richard Holbrooke had corralled the three leaders — Alija Izetbegović, Franjo Tuđman, and Slobodan Milošević — into a single air base and conducted a grueling proximity negotiation, shuttling between delegations in adjacent buildings. The resulting General Framework Agreement divided Bosnia into two entities: the Federation of Bosnia-Herzegovina (Bosniak-Croat) and Republika Srpska (Serb), linked by weak central institutions. A NATO Implementation Force (IFOR) of 60,000 troops would enforce the agreement on the ground.

February 28, 1998 – June 10, 1999 · Kosovo Theater

The Kosovo Liberation Army (KLA) had been waging a guerrilla insurgency against Serbian security forces since 1996, but full-scale war erupted in February 1998 when Serbian police and military launched massive counter-insurgency operations that killed entire families in villages suspected of harboring KLA fighters. The Račak massacre of January 1999 — in which Serbian forces killed 45 Albanian civilians — crossed a threshold that NATO could not ignore after Srebrenica. When peace negotiations at Rambouillet failed in February 1999, NATO launched its air campaign. Serbian forces simultaneously accelerated a systematic campaign of ethnic cleansing, expelling over 850,000 Kosovo Albanians into Albania and Macedonia in a matter of weeks. The combined weight of NATO bombing and international pressure finally forced Yugoslav forces to withdraw from Kosovo in June 1999.

March 24 – June 10, 1999 · Federal Republic of Yugoslavia Theater

For 78 days, NATO aircraft struck targets across the Federal Republic of Yugoslavia in the alliance's largest military operation since its founding. The campaign, named Operation Allied Force, targeted Serbian military infrastructure, air defense systems, fuel depots, bridges, and communications networks. As the bombing intensified, Serbian forces accelerated the ethnic cleansing of Kosovo, expelling over 850,000 Albanians in an attempt to pre-empt a NATO ground invasion by creating a humanitarian catastrophe that would split the alliance. NATO planners faced constant political pressure: strikes on civilian infrastructure — including the Chinese embassy, accidentally hit on May 7 — generated fierce international criticism. The campaign ended when Milošević accepted an internationally supervised withdrawal of Serbian forces from Kosovo.

October 5, 2000 · Belgrade Theater

After losing the September 24, 2000 presidential election to opposition candidate Vojislav Koštunica, Slobodan Milošević attempted to falsify the results — as he had done in 1996. This time, the country refused to accept the fraud. On October 5, hundreds of thousands of Serbs from across the country converged on Belgrade; miners from Kolubara who had been on strike for weeks led a column of bulldozers and work vehicles toward the Federal Parliament building. Police melted away or joined the protesters. By evening the parliament building was in flames and Milošević had lost power. He was arrested by Serbian police in April 2001 and transferred to the ICTY in The Hague in June — the first sitting or former head of state to face an international war crimes tribunal.