The war in Yugoslavia was motivated by energy interests. Kosovo's majority Muslim Albanian population wanted independence from Serbia after communism, which threatened Russian influence in the region. If Yugoslavia and Greece had blocked it, the proposed AMBO pipeline transferring Caspian oil to Europe via the Adriatic Sea would have antagonized Russian oil and gas interests. NATO intervened in the conflict and established an autonomous Kosovo, allowing the pipeline project to proceed securely through the region.

1. The AMBO Pipeline and the
War in Yugoslavia
–
Another Energy War
Iakovos Alhadeff

2. The war in Yugoslavia (Serbia) was another energy war. The population of Kosovo,
in the southern part of Serbia, is 90% Muslims of Albanian origin as you can see at
the following Wikipedia link. These people wanted to be independent from Serbia
after the end of the communist period
http://en.wikipedia.org/wiki/Kosovo_Albanians
These separatists were embraced by the Americans and the Europeans. Before the
creation of the Former Yugoslav Republic of Macedonia (brown region) and the
creation of Kosovo (green region), were both former parts of Yugoslavia. Yugoslavia
together with Greece, both close Russian allies, could block oil or natural gas
pipelines that could transfer Caspian oil or natural gas from the Black Sea to the
Adriatic Sea, since these American and European pipelines would antagonize the
Russian oil and natural gas industry.

3. As you can see at the following link, the AMBP pipeline, is an oil pipeline
transferring Caspian oil to the Adriatic Sea, following the route Ajerbaijan-Turkey-
Bulgaria-FYROM-Albania-Adriatic Sea-Europe (black line on the map), which has
been already agreed, but which has not been developed yet, as you can read at the
following Wikipedia link.
http://en.wikipedia.org/wiki/AMBO_pipeline
Hence, the Kosovars of Albanian origin started protesting requiring their
independence, the Serbs used violence against them, and on February of 1998, a
NATO operation under the code name Operation Allied Force attacked Serbia. The
attacks were carried out by 13 countries, namely U.S.A., Canada, Great Britain,
France, Germany, Belgium, Netherlands, Spain, Portugal, Italy, Norway, Denmark
and Turkey.
These countries attacked Serbia and forced Serbia to accept an autonomous Kosovo.
A large NATO base was established in Kosovo, namely the Kosovo Force, which
would see that Albanian Kosovars were not threatened by the Serbs, and that any
future pipelines crossing the region would be secure too. You can read about Kosovo
Force in the following Wikipedia link.
http://en.wikipedia.org/wiki/Kosovo_Force
The following link is a good chronological summary of the NATO attack in Serbia.
http://www.jfcnaples.nato.int/page7196179.aspx