Following the election of Franjo Tuđman as President of Croatia in 1990, the country’s Serbs were worried—and with good reason. Avowedly nationalistic, Tuđman had forged a reputation for challenging the Serbian—and more importantly, Serb—dominance of Yugoslavia even in the 1970s, a dissidence for which he was briefly imprisoned by Tito. By the late 1980s, as Yugoslav collapse seemed likely, if not inevitable, Tuđman positioned himself at the head of the resurgent Croatian nationalist movement. Although they did not at first openly demand independence, their ultimate goal was clear: an independent Croatian state, run by Croats, run for Croats.

But Croatia was not wholly Croat; far from it. Roughly twelve per cent of the Croatian population were Serbs, who lived mostly in the majority-Serb areas in the northeast and centre of the country. The Croatian Serbs had much to fear from a nationalist Croatian government: in World War II Croatia had been ruled by the Ustaše, an ultranationalist, anti-Serb, pro-Catholic, pro-Axis fascist movement that massacred Croatian Serbs with ruthless efficiency.

Tuđman’s movement, for its part, did little to allay these fears. Tuđman publicly minimised the numbers of people killed at Ustaše concentration camps, particularly Jasenovac. The movement as a whole adopted as their symbol the “šahovnica”, the famous red-and-white checkerboard flag that had been the official national symbol of the Ustaše.

Alienated by the newly elected Croatian government, the Croatian Serbs responded by severing all ties to it. The Serb Democratic Party broke from the Croatian parliament in May 1990; the wider Serb public followed, and the process of secession began. Serbs set up roadblocks severing the Serb areas in central and northeastern Croatia from the rest of the country, effectively establishing an independent state which eventually became known as the Republika Srpska Krajina. Their reasoning perhaps was understandable: the Croatians had, after all, used the same arguments when justifying their own secession from Yugoslavia.

Things in the former Yugoslavia, though, are never simple. Croatia’s populace, fractal-like, exposes minorities within minorities at every scale: and so, just as Croatia was home to substantial Serb minorities, the so-called Serb areas within Croatia were home to their own Croat minorities. These were not two distinct populations, between whom the borders had simply to be rearranged; they merged and faded across each other, and there was much in dispute.

As the Croatian War progressed, it was on these battlegrounds that the conflict was to be fought and lost. Croatian Serbs, aided by the JNA and the Serbian secret services, put up staunch resistance to the Croatian army. By 1992 the front lines had, for the most part, settled, and the Serb forces had cemented their control of the breakaway regions; the next three years saw only limited territorial exchanges. It looked, for a while at least, as though the independence of the Serbs in Croatia might become a political reality, as would eventually happen in Bosnia. But in 1995, the Croatian military launched a series of offensives that were to dash any hopes for an independent Serb Krajina.

The first Croatian operation was, while modest in ambition, of pressing strategic importance. Codenamed Operation Flash, the plan’s aim was to retake for Croatia the breakaway Serb region known as the Serbian Autonomous Oblast of Western Slavonia (SAOZS), located at the westernmost extremity of Slavonia in the northeast of Croatia. Although its borders had remained static since their declaration in 1991, if left unchecked Serb forces there could theoretically advance to Croatia’s northern border, severing all of eastern Croatia from Zagreb—thereby striking a devastating strategic blow to Croatian forces and greatly expanding the territory under their control.

In 1992, the Croats had launched a series of small-scale offensives that had driven southwards towards the Bosnian border, reducing the SAOZS to a relatively small pocket. But it remained, and remained a high priority for the Croats; and so, inevitably, it was the first target in the summer of 1995. The plan was to strike simultaneously from the north, east and west, surging through the oblast and overwhelming the Serb forces with superior weaponry.

In the end, the operation was so swift and so successful as almost to be anticlimactic. In the morning of 1 May, 7,200 Croat soldiers stormed into the oblast; in a matter of hours the 8,000-strong Serb force surrendered, 283 of its number killed and 1,500 captured. Western Slavonia had returned to Croat control; the tide had turned, and the Croats could now target the rest of the Krajina. First, though, there was the matter of the Bosnian Serbs to the south.

By the summer of 1995, the Bosnian Serbs had made huge territorial gains and controlled vast swathes of Bosnia. In western Bosnia, where most of Bosnia’s Croat population was or had been concentrated, just one tiny pocket in the northwest, surrounding the town of Bihać, remained outside Serb control. This territory spanned almost the whole length of the Croatian-Bosnian border, over which the Bosnian Serbs helped supply their Croatian counterparts with supplies and materiel.

This western region of Bosnia was not only important from the perspective of the Bosnian Croats; it also held the key to the Croatian army’s desire to capture Knin, the town in central Croatia that had been the starting point and the ideological focal point of the Serb resistance since 1991. Knin was less than ten miles from the Bosnian border; an opportunity to sever its supply lines was too tantalising to miss.

In July 1995, encouraged by their efforts in Western Slavonia, the Croatian army hatched a plot to retake these areas of western Bosnia, and in the process sever Knin’s supply lines. In the aptly named “Operation Summer ’95”, Croatian forces advanced north from Herzegovina in southern Bosnia with all the swiftness that had characterised Operation Flash. This time, however, they met with stiff resistance from the Bosnian Serbs, who were far better equipped than had been the Croatian Serbs; after all, they had by 1995 enjoyed three years of support from the JNA and the Serbian intelligence services.

Eventually, though, the Croatians prevailed, and carved out a corridor in western Bosnia that spanned 1600km². The road from the Republika Srpska to Knin was now in Croatian hands: with no chance of resupply from the Bosnian Serbs, Knin and the surrounding Serb territory was living on borrowed time. The stage was set for the Croatian coup de grace: in August, it was delivered.

Operations Flash and Summer ’95 had weakened the Croatian Serb forces to an almost fatal degree. Although Slobodan Milošević had promised to assist the Krajina Serbs with materiel and intelligence, they still remained incredibly vulnerable to a concerted Croatian offensive. The balance of power had in just a few months shifted entirely. It was something the Croatians were well aware of; when the EU and US proposed a diplomatic solution that would see Serbs given autonomy within Croatia—but short of the independence they had previously requested—it was rejected outright by Croatian negotiators. With the Serbs on the ropes, the Croats had one thing on their minds: revenge.

Before dawn on 4 August 1995, 150,000 Croatian troops assembled along a 300 kilometre front in preparation for what was to be the largest military offensive in Europe since World War II. Their plan was textbook blitzkrieg: elite Crotian Guards Brigades would advance rapidly, while less elite units held their continually advancing lines before surrounding and destroying the remaining enemy pockets. It worked perfectly; though predictably strong resistance was encountered in places, the Serb capitulation was inevitable in the face of such a well-organised and well-equipped enemy.

Over the next few days, the Croatian advance was precipitate. By 5 August, they had captured much of Dalmatia; by 6 August, they had reached the Bosnian border and captured, finally, the town of Knin. Tuđman staged an exultant victory celebration in Knin as the šahovnica was raised above the town’s ancient fortress; the Croatian Serbs were, for all intents and purposes, crushed. Over the next few days, Croatian troops mopped up the last remaining resistance, and on 9 August the Serbs formally surrendered.

Just under a thousand soldiers were killed in all: 700 Serbs, and around 200 Croatians. The real victims, though, were the Serb inhabitants of the Krajina. Estimates vary as to the number of civilians displaced in the offensive; predictably, the numbers vary wildly depending on the ethnic sympathy of the source. Serb sources claim as many as 250,000; the actual figure is likely between 150,000 and 200,000, two-thirds of the total number displaced in the whole war.

Most controversially, the flight of these refugees had been planned in advance, with the help of the UN who were faced with a stark choice: condemn the Serb populace to possible murder or to certain expulsion. Corridors were built in to the Croatian’s planned battle lines, through which the Serb populace fled naturally into Bosnia; it was some of the most effective ethnic cleansing ever perpetrated. While the Serbs were in flight, there were incidents of arson and property destruction that left Serb villages uninhabitable were their original population to return. To make matters worse, those refugees who managed to reach Serbia were then conscripted into the Serbian armed forces and sent to Slavonia. Many were mistreated for their perceived failure to defend the Krajina.

Following the end of the war, Operation Storm was one of the highest priorities for the International Criminal Tribunal for the former Yugoslavia. Authorisation for the operation had extended to the highest levels: had Franjo Tuđman not died in 1999, he would have been indicted for war crimes committed during the operation. As it is, though, there are three indictees at the tribunal: Ante Gotovina, then a commander in the Croatian army; Ivan Čermak, then the Assistant Defence Minister; and Mladen Markač, then head of the Croatian Special Police.

For convenience, their trials have been condensed into one. Without wishing to tempt fate, proceedings seem to be progressing with some speed—by the standards of the ICTY, at least. The defendants were indicted in 2006; the trial began in March 2008; by March 2009, the prosecution had concluded; in May 2009 the case for the defence began. Within the next six months, then, there is the very real possibility of a final verdict. Though the Croatian Serbs will likely never attain autonomy within Croatia, and though most of those displaced have still not been able to return to their homes and may never be able to, the prospect of justice at the ICTY offers the prospect of at least some measure of closure for those whose lives were altered forever in that long and bloody summer of 1995.