This thesis analyses the past and present development of Croatia and the Euro-Atlantic political, military and economic spheres. It suggests that the next logical step on the way to a stable and prosperous Southeastern Europe is Croatian admittance to NATO. Croatian membership in NATO is arguably conditio sine qua non for the process of regional stabilization and democratization. This policy became obvious when democratic developments in Croatia in 2000 caused positive changes in Bosnia and Herzegovina, and in Serbia. The changes in Croatia, accompanied by promising economic achievements and sufficient civilian control over the military, opened the door for Croatia to enter Euro-Atlantic institutions. All the aforementioned achievements, along with Croatia's contribution to Partnership for Peace and increasing international cooperation in other areas, strongly suggest Croatia's potential for becoming a full-fledged NATO member and is a significant factor in increasing the security of the region. The thesis argues by providing historical, economic and political facts, that in the present situation, all necessary requirements for NATO membership have been satisfied by Croatia. Therefore, acceptance itself is thus only a political decision of the NATO members. The thesis provides evidence that Croatia has become equally or better prepared than other serious aspirants to be a member of NATO by providing a comparative overview of the basic data considered for admission to NATO. It also demonstrates that Croatian membership represents a significant benefit to the Alliance and contributes to the achievement of the basic NATO goals in Southeastern Europe. Additionally, the thesis addresses various benefits that the neighboring countries might reap from Croatian membership in the Alliance, which will enhance not only regional, but also European security.