Domagoj said:
What were it's true reasons, motives? Who was truly in control, who managed the behind the curtain operations?
This is an interesting question, you might want to see this documentary which is trying to find the answers:
_http://www.b92.net/specijal/vukovar-eng/
From the sinopsis:
We have tried to comprehend why Vukovar, a rich Slavonian town famous for being a "miniature Yugoslavia," Tito's exemplary town of unity, was the one location to suffer total apocalypse, one comparable to the sacrifice and siege of Stalingrad, and by the extent of destruction, and scenes shown around the world, reminiscent of Hiroshima and Nagasaki.
Why was a city which had no strategic interest in military and police force formations in the conflict between the Yugoslav National Army and the Croatian military, so systematically destroyed while the Serbian (Milosevic) and Croatian (Tudjman) leaders walked around Tito’s estate all the while, discussing plans for a new division of Yugoslavia?
Domagoj said:
The JNA - "Yugoslavian National Army". Basically the Serbian Army, the commander who was in charge off the attack was a serbian Veselin Šljivančanin.
Actually it was Serbian Territorial Defense and paramilitary formations who carried out the massacre. According to International Criminal Tribunal findings Yugoslav Army forces were pulled back from the Ovcara ( site of massacre).
Domagoj said:
and the acquitting verdict in Hagg for generals Markac and Gotovina who managed the militiray operation Oluja which ended the war, freed and saved the Croatian people.
It should also be mentioned that during this operation Storm, which was entirely planned and supported by NATO many Serbian civilians ( mostly disabled and elderly who were unable to leave ) were massacred and 90% of serbian houses burned to the ground. Also the civilian refuge convoys were bombed in the aftermath of this operation. This is a far cry from as you say "freeing and saving Croatian people" as practically no Croats lived in those areas. it was more about the strategic and economic interests as Serbian rebels held the access to the sea and were effectively splitting the Croatia in two halves.
At the International Tribunal some evidence emerged that Croatian President actually planned ethnic cleansing of Serbs who occupied border regions of Croatia:
"On 31 July 1995, a meeting of Croatia’s top military and political leadership was held on the island of Brijuni.Tudjman apparently spoke about "blows that will make the Serbs all but disappear, in other words, those we don’t reach immediately, must capitulate in the next few days."
The transcript of the meeting later formed the basis of the United Nations war crimes tribunal for the former Yugoslavia's allegation of a joint criminal enterprise found in the indictment against generals Ante Gotovina, Ivan Cermak and Mladen Markac. The prosecution of the ICTY alleged that the content of the meeting was evidence of existence of a joint criminal enterprise to forcibly remove the Serb population from Croatia and prevent their return.According to the prosecution, the Brijuni Transcripts demonstrated a shared intent to forcibly remove Serbs from the area through means such as shelling, destruction, looting, intimidation, and violence, while the defense maintains that Tudjman specifically spoke about rebel Serb military units when he referred to Serbs needing to "all but disappear"
The Croatian Chief State Prosecutor's Office has verified the authenticity of the recording of the Brijuni meeting.[41][42] Tudjman's words indicate his intent to move the civilian population out of the area while issuing false human rights guarantees."
This is why Croatian generals you mention were indicted and found guilty at first but recently this ruling has been reversed.
There are some indications these two generals were sacrificed in order for Croatia to be able to join EU and after this has been accomplished their sentence has been reversed and they were acquitted of the charges. Stinks of high level political intrigue with little regard for victims on both sides.