On May 1, 1995, Croatian Army troops launched an offensive aimed at regaining control of Serb-held lands in western Slavonia, an area designated as a "United Nations Protected Area." By May 4, Croatian government troops had recaptured the area. During the week of May 8, we traveled to Croatia to assess the behavior of Croatian troops during and immediately after the offensive. Based on information gathered during that trip and additional evidence made available as of June 10, violations of the rules of war appear not to have been widespread. But violations of humanitarian and human rights law did take place during and after the offensive, and many allegations require still further investigation.