in English The most potent threat to the security and stability of the state in some geographical regions after the cold war has been the proliferation of VNSA due largely to the declining capacities of states especially in the developing world. For a myriad of reasons, the modern nation-state seems incapable of performing its functions and fulfilling the obligations of the state to its citizens. Moreover, the state appears to have lost its monopoly on the use of force within its territory, a situation which has led to the prevalence of swathes of ungoverned territory with marginalized and aggrieved communities whose resentment against central authority find resonance with Non-State Armed Groups whose violent contestation of state authority has further contributed to state fragility and increased insecurity. The Sahel region is one that represents this dynamic in all of its dimensions.

This thesis aims to investigate the impact of state fragility on capital inflows and economic growth in Nigeria over the period 1980-2015. In line with existing studies, it adopts an augmented neoclassical growth model where capital is divided into domestic and foreign capital inflows (FDI, ODA and Remittances). Using an autoregressive distributed lag (ARDL) bounds testing approach to co-integration, significant long-run relationship was confirmed between state fragility, capital flows and economic growth. The results reveal domestic capital to be very significant and contribute positively to economic growth. Similarly it was observed that remittances remain a very crucial form of capital flow to Nigeria and that the presence of state fragility makes it more significant. For ODA a positive contribution to economic growth was observed, however, the presence of state fragility renders it insignificant. In the case of FDI, the study found a negative relationship between FDI and economic growth albeit insignificant. However, the presence of state fragility makes it significant but still negative. A negative relationship was also observed between state fragility and economic growth. These findings, implies that while the issue of state fragility needs to be addressed and concerted efforts put into building state resilience, not just for the direct impact of state fragility on the economy, but also its impact on the economy through other channels such as capital flows.

This thesis will work on implementing the Political Economic Theory of Wall Construction on the case of Saudi Arabia. To further contribute to the study of border walls, the PETWC is applied to a different methodology than in the original paper where it was first introduced, taking into consideration neighboring countries without border walls into analysis. Ultimately, the thesis will show that PETWC sets good foundation for further development of a broader border wall theory, and that border walls concerning Saudi Arabia are consequence of low regional integration and internal instability at home and abroad.

The aim of the work Failed States in International Relations is the examination of this phenomenon regarding the terminological discrepancy, causes of the state fragility, security and social aspects and the various attitudes from the side of the international communities. A special part is dealing with so called "successfully failed states" where despite the obvious non-functioning the state is able to survive due to the revenues from the natural resources. The ?ndings are represented on the case study of the Democratic Republic of the Congo - a country with huge potential but miserable performance by now.

La Communauté Economique des Etats d’Afrique de l’Ouest est une organisation internationale qui s’est très tôt impliquée dans le maintien de la paix et de la sécurité. Elle a entrepris des interventions militaires dans certains Etats ouest-africains, comme le Libéria, la Sierra Léone, la Guinée Bissau, dans les années 1990. A partir de 1999, la CEDEAO a procédé à une réorientation stratégique en matière de sécurité. Celle-ci s’est manifestée par l’adoption d’un nouveau mécanisme de sécurité visant à placer l’individu au cœur des préoccupations sécuritaires. Le nouvel objectif de la CEDEAO est de réaliser la sécurité humaine au profit des citoyens ouest-africains. Il se trouve que la réalisation de la sécurité humaine nécessite des moyens économiques et financiers, or les Etats ouest-africains sont parmi les plus pauvres du monde. Aussi, depuis l’adoption du nouveau mécanisme de sécurité, la CEDEAO rencontre de plus en plus de difficultés à concrétiser les nobles recommandations et principes contenus dans son ordonnancement juridique, dans un contexte marqué par l’accroissement des menaces militaires contemporaines et des menaces non militaires.Après plus de 30 ans d’expériences dans le processus d’intégration, n’est t-il pas désormais évident que la réussite de l’organisation dans le maintien de la paix et de la sécurité est intimement liée au progrès accompli dans l’intégration économique ? La faiblesse des perspectives économiques des Etats de la CEDEAO n’appelle-t-elle pas à modifier la stratégie d’intégration de la CEDEAO ? L’adoption du fédéralisme à l’échelle ouest-africaine ne peut-elle pas constituer une voie salvatrice pour la CEDEAO ? / The Economic Community of West Africa is an international organization that was involved very early in the peacekeeping and security. It undertook military intervention in some West African states, like Liberia, Sierra Leone, and Guinea Bissau. In 1999, ECOWAS has made a strategic shift in security. This was manifested by the adoption of a new security mechanism to place the human at the heart of security concerns. The new objective of ECOWAS is to achieve human security for the citizens of West Africa. It turns out that the realization of human security requires economic and financial means, or the West African states are among the poorest in the world. Also, since the adoption of the new security mechanism, ECOWAS meeting more and more difficult to achieve the noble principles and recommendations contained in its legal system, in a context of increased of contemporary military and non military threats. After over 30 years of experience in the integration process, is there not now clear that the success of the organization in peacekeeping and security is closely linked to progress in the economic integration? The weak economic outlook states of ECOWAS calls does not change the strategy of integration of ECOWAS? The adoptions of federalism across West Africa cannot it be a way of salvation for ECOWAS?