DTA, the issue was never about legitimate Serb actions against Haradinaj and the KLA. As documented in the December 1999 U.S. Government Report:
Ethnic Cleansing in Kosovo-An Accounting, the problems were Forcible Displacement of Ethnic Albanian Civilians, Summary Executions, Looting of Homes and Businesses, Widespread Burning of Homes, Use of Human Shields, Arbitrary Detentions, Rape, Violations of Medical Neutrality, and Identity Cleansing; to borrow the sub-headings for the report. Go to the link and you can get the details about the million plus Albanians forced from their homes by the Serbs, the 500 burned villages and so on.
War is hell and that is the reason why it is condemned in International treaties. That was the rationale behind Nuremberg. Nazis were prosecuted because they STARTED WAR, A CRIME AGAINST PEACE. Allies were not prosecuted for Dresden and murder and rape of German civilians.
Crime against peace, as well as support of terrorism is forbidden by international treaties.
All you have described allegedly happened after NATO agression on Yugoslavia March 24 1999.
All guilty for crimes should be trialed. Serbs for commiting crimes against Albanian civilians, Germans and Americans for crime against peace and being part of criminal enterprise.