This study is devoted to the geopolitical stakes in relations between Morocco and Spain: realities, challenges and prospects. It is divided into four parts: the first deals with the issue of territorial disputes and differences between Morocco and Spain from the 10th century to 2023; the second focuses on the geopolitical issues that led Spain to recognize Morocco's proposed plan for autonomy for its southern Saharan provinces, as the one and only peaceful, reasonable, acceptable, credible and most serious proposal for definitively resolving the problem of the Moroccan Sahara within the framework of its sovereignty. The third will be devoted to transport infrastructure in both countries, and the fourth to logistics and trade between Morocco and Spain.