Boundaries between states, determined as a result of a variety of political, historical and administrative compromises, may be controversial, ambiguous and unstable. Dissatisfaction over a boundary decision may persist long after the signature of the agreement which gave rise to it. Such agreements may be ambiguous as to the exact boundary line if the area is poorly mapped, or if the natural features on which the boundary is based are displaced, as can happen when a river changes its course for instance. This may give rise to boundary disputes, particularly if the displacement process is not recognized.
Until recent times the exact boundary limits of states and their jurisdictions were not defined. Borders were frequently not marked in any way. The need for fixed and marked boundaries only arose with the concept of the nation state, and it was only in recent times that surveying and cartographic techniques permitted boundaries to be established unambiguously.
More than 80 territorial and border disputes are currently unresolved including: Alto Adige/South Tyrol between Austria and Italy; four of the Kuril Islands occupied by Russia and claimed by Japan; Taba between Israel and Egypt; the McMahon Line recognized by India but disputed by China; and the borders between Mali and Burkina Faso, Saudi Arabia and Oman, Saudi Arabia and South Yemen, India and Bangladesh, India and Pakistan, and Kuwait and Iraq.