Macgregor was Clark’s number one guy back then and was the architect of NATO’s air war against Serbia. Macgregor was a big fan of cluster bombs.
From GROK:
Douglas Macgregor’s Role in the Kosovo War
Colonel Douglas Macgregor, a retired U.S. Army officer, played a significant role as a planner under General Wesley Clark during NATO’s 1999 air campaign against Serbia, known as Operation Allied Force. Specifically, Macgregor served as the Director of the Joint Operations Center at NATO’s Supreme Headquarters Allied Powers Europe (SHAPE) during the Kosovo War. In this capacity, he was a key planner, contributing to the strategic and operational aspects of the 78-day bombing campaign aimed at halting ethnic cleansing in Kosovo by Serbian forces under Slobodan Milošević. His work involved coordinating and developing plans for the air operations, which were central to NATO’s strategy of using air power to pressure Serbia without deploying ground troops initially. For his contributions, Macgregor was awarded the Defense Superior Service Medal.