Operation Horseshoe

Operation Horseshoe was a 1999 alleged plan to ethnically cleanse Albanians in Kosovo. The plan was to be carried out by Serbian police and the Yugoslav army. Claims that the plan was being implemented were NATO's justification for their bombing of Yugoslavia during the Kosovo War. 
Human Rights Watch said that in early 1999, the Yugoslav army and the Serbian police "in an organized manner, with significant use of state resources" conducted a broad campaign of violence against Albanian civilians to expel them from Kosovo and thus maintain political control of Belgrade over the province.
In 2011, former Bulgarian Foreign Minister Nadezhda Mihaylova (Neynsky) revealed in a TV documentary that the Bulgarian government had turned over to Germany an unverified report compiled by its military agency which "made clear" the existence of the plan, even though the military intelligence warned that the information could not be verified.
Horseshoe plan.
Horseshoe plan (German: "Hufeisenplan") was an alleged Yugoslavian plan to expel the Albanian population of Kosovo. The operation's title suggest that the Yugoslav Army and police would squeeze the Kosovo Liberation Army (KLA) and civilians in an attack launched from three sides, driving out the population as refugees fled through the open southwestern end of the horseshoe into Macedonia and Albania.
The plan was detailed by German Foreign Minister Joschka Fischer in a press conference on 7 April 1999. He stated that the German government had unearthed operational plans agreed by Yugoslav commanders in late February 1999 to carry out a massive ethnic cleansing operation in Kosovo. According to Fischer, this had been put into effect as early as March 1999 — a month before the start of NATO operations — when Yugoslav President Slobodan Milošević had told him that "he would be finished with the ethnic Albanian separatists within a week". Fischer accused Milošević of engaging in "ethnic warfare" directed against his own people, in which a whole ethnic group had become the "victim of systematic expulsion" to "reorient the political geography" of Kosovo.
Reports from other countries supported Fischer's allegations. "The Times" of London reported on 8 April that:
Further details were provided on 9 April by Rudolf Scharping, the German Defence Minister, at a press conference held in Bonn. He presented maps containing the names of towns and villages which showed arrows representing Yugoslav army and police militia units progressively encircling Kosovo in a horseshoe-shaped pincer movement. He was quoted as saying that: "Operation Horseshoe provided clear evidence that President Miloševic (sic) had long been preparing the expulsions from Kosovo and that he had simply used the time gained by the Rambouillet peace talks to organise army and police units for the campaign."
The "Baltimore Sun" suggested on 11 April that NATO had known about the Horseshoe plan for some time, but had underestimated its severity. The then British Foreign Secretary later supported the German reports, telling a parliamentary committee "that there was a plan developed in Belgrade known as Operation Horseshoe which was for the cleansing of Kosovo of its Kosovo population. That plan has been around for some time." 
According to Radio Television of Serbia the report was drafted by Bulgarian intelligence services based on the analysis of early 1999 events. 
Former Bulgarian foreign minister Nadezhda Neynsky acknowledged in 2012 that the then-Bulgarian government had delivered information to Germany and NATO about Milošević's alleged plan to ethnically cleanse Kosovo. She said she had delivered the document about the operation to the then German foreign minister, Joschka Fischer, in April 1999, although Neynsky had denied doing so in March 2000. Neynsky stressed that Germany's Foreign Minister Fischer took the report of the Bulgarian military intelligence very seriously. She also said the Bulgarian government back in 1999 decided to provide NATO with the report on the Horseshoe plan even though Bulgarian military intelligence warned that the information could not be verified.
Yugoslav Army military operations.
Operations before NATO intervention.
Yugoslav Army military response to KLA attacks culminated in Operation Horseshoe directed not only against KLA fighters but also including systematic expulsions of Kosovar civilians. During the armed conflict in 1998 Yugoslav Army and Serbian police used excessive and random force, which resulted in property damage, displacement of population and death of civilians 
Some date Operation Horseshoe's effective beginning to the summer of 1998, when hundreds of thousands of Kosovar Albanians were driven from their homes.
Withdrawal of Organization for Security and Co-operation in Europe monitors, together with the start of NATO's bombing campaign, encouraged Milošević to implement this "orchestrated elements to the campaign of expulsions, which could be described as a plan". On 20 March 1999, the Serbian offensive, known as Operation Horseshoe, was already in motion.
Operations after NATO intervention.
With the beginning of NATO bombing of Yugoslavia on 24 March 1999, Serbian forces accelerated Operation Horseshoe. 
In 1999, the Yugoslav Army, Serbian police and Serb paramilitary, in an organized manner, with significant use of state resources, conducted a broad campaign of violence against Albanian civilians to expel them from Kosovo and thus maintain political control of Belgrade over the province.
According to the legally binding verdict of the ICTY, police after the NATO bombing of Yugoslavia (24 March 1999), federal Army and Serbian police systematically attacked villages with Albanian population, abused, robbed and killed civilians, ordering them to go to Albania or Montenegro, burning their houses and destroying by their property. 
Within the campaign of violence, Albanians were expelled en masse from their homes, murdered, sexually assaulted, and their religious buildings destroyed. Serbian forces committed numerous war crimes during the implementation of "joint criminal enterprise" whose aim was to "through the use of violence and terror, force a significant number of Kosovo Albanians to leave their homes, across the border, the state government to retain control over Kosovo." 
Ethnic cleansing of the Albanian population is performed by the following model: first the army surrounded a place, then followed the shelling, then the police entered the village, and often with them and the army, and then crimes occurs (murders, rapes, beatings, expulsions...).
identity cleansing, consisting of "confiscation of personal identification, passports, and other such documents to make it difficult or impossible for those driven out to return", was then reportedly employed. 
Expelled Kosovar Albanians were systematically stripped of identity and property documents including passports, land titles, automobile license plates, identity cards and other documents. Physicians for Human Rights reports that nearly 60 percent of respondents to its survey observed Serbian forces removing or destroying personal identification documents. This criminal practice suggesting the government was trying to block their return.
In addition to confiscating the relevant documents from their holders, efforts were also made to destroy any actual birth records (and other archives) which were maintained by governmental agencies, so as to make the "cleansing" complete.
Number of refugees.
According to the United Nations High Commissioner for Refugees, by March 1999 (prior to NATO bombing), more than 200,000 Albanian civilians were internally displaced, almost 70,000 Albanians had fled the province to neighboring countries and Montenegro, and a further 100,000 Yugoslav nationals, mostly Kosovar Albanians, had sought asylum in Western Europe. Also, thousands of ethnic Albanian villages in Kosovo had been partially or completely destroyed by burning or shelling.
Within three weeks of the start of NATO strategic bombing during the Kosovo War, there were 525,787 refugees from Kosovo in neighboring countries. A month later, on 12 May, the total number of refugees had risen to 781,618. By June 1999, the Yugoslav military, Serbian police and paramilitaries expelled 862,979 Albanians from Kosovo, A claim disputed by many Serbian politicians. and several hundred thousand more were internally displaced, in addition to those displaced prior to March. 
Approximately 440,000 refugees crossed the border to Albania and 320,000 to Macedonia. Montenegro hosted around 70,000 refugees, while Bosnia and Herzegovina received more than 30,000. Amnesty International estimated that "nearly one million people have been forced to flee Kosovo".
Radio Television of Serbia never showed the columns of Albanians expelled by Serbian police and paramilitaries, except when a convoy of fleeing Albanians was killed by NATO bombs. Moreover, Milošević's propaganda trying to convince international public that huge columns of refugees fleeing Kosovo because of NATO's bombing, not Yugoslav Army military operations.
Indictments.
The International Criminal Tribunal for the Former Yugoslavia charged Slobodan Milošević and other Yugoslav officials with crimes against humanity including murder, forcible population transfer, deportation and persecution of Kosovo civilians:
Presiding Judge Iain Bonomy when imposing sentence said that "deliberate actions of these forces during the campaign provoked the departure of at least 700,000 ethnic Albanians from Kosovo in the short period from late March to early June 1999."
Controversy.
The existence of the Horseshoe plan was immediately denied by the Yugoslav officials. Slobodan Milošević labeled it as a "fabrication of the German Defence Ministry". Milošević denied a policy of ethnic cleansing during the NATO bombing in Kosovo, stated that "when aggression stops, when bombing stops, then it will be very easy to continue (the) political process".
Ratomir Tanić, a witness at Milošević's subsequent war crimes trial, said that Horseshoe was a colloquial nickname for a "completely different" Yugoslav army plan, that should come into effect only if the ethnic Albanian population take the side of the foreign aggressor in case of aggression on Yugoslavia. Then the Army would "neutralising the Albanian strongholds". Tanić stated that the army leadership didn't use this plan during the Kosovo War, "because there was no external aggression or Albanian rebellion".
In April 2000, Heinz Loquai, a retired German brigadier general, published a book on the war that claimed that the German government's account had been based on a general analysis by a Bulgarian intelligence agency of Yugoslav behaviour in the war, which was turned into a specific "plan" by the German Defence Ministry. According to Loquai, the Bulgarian analysis concluded that the goal of the Yugoslav government was to destroy the Kosovo Liberation Army, and not to expel the entire Albanian population. He also pointed to a factual flaw in the German government's presentation - it had named the plan "Potkova", which is the Croatian and Bulgarian word for horseshoe, whereas the Serbian word is "potkovica".
Aftermath.
It is unclear how much advance planning there was for the ethnic cleansing of Kosovo, but the removal of ethnic Albanians was counterproductive as, according to British reporter and political analyst Tim Judah, it removed any possibility that Serbia would be allowed to retain control of Kosovo. The government of Serbia did not expect NATO to initiate its bombing campaign. The systematic destruction of Kosovo Albanian identity documents would have made it more difficult for them to prove their citizenship.