Both Statement-I and Statement-II are correct, and Statement-II explains Statement-I. The security situation in the Sahel region is indeed unstable and worsening, as highlighted by various reports indicating ongoing violence and attacks by non-state armed groups. Additionally, there have been recent military takeovers or coups in several Sahel countries, including Mali, Burkina Faso, and Niger, which have contributed to the instability in the region. The military juntas that came to power through these coups have further exacerbated the security challenges, thereby explaining the instability mentioned in Statement-I.