Why do international borders make it difficult for governments to fight rebels based abroad?

International borders complicate a government's ability to combat rebels based abroad primarily because they formally delineate state sovereignty. While borders are often physically easy to cross from a military perspective, the legal and diplomatic status of these boundaries creates significant constraints for state forces attempting to pursue insurgents into neighboring territories.1

Because these borders represent the limits of a government's jurisdiction, military action against rebels based in another state can lead to international friction or conflict. Furthermore, the existence of these borders allows insurgent groups to exploit the political divide between states, often receiving support from rival governments or utilizing the neighboring territory as a sanctuary for mobilization and the acquisition of arms. Consequently, the international nature of these conflicts often links civil wars to broader interstate tensions, making it difficult for a government to neutralize threats that operate beyond its own sovereign reach.1