This article presents the development of expeditionary capabilities as the key driver for transforming air forces. It provides an overview of the progress made by most of the small NATO nations and the deployment of their air expedi­tionary force packages in the Alliance missions and operations. The cooperative development of such capabilities is another factor driving transformation, in par­ticular accounting for limited and further decreasing defence resources. Some rec­ommendations are provided for the Bulgarian Air force in developing jointly de­ployable air capabilities with the neighbouring and other allied nations.