Territorial sovereignty refers to a state's exclusive right to exercise its governmental powers within a defined territory. For newly emerged states, the acquisition of territorial sovereignty is a critical process, often linked to historical events like decolonization, dissolution of empires, or secession. While traditional modes of acquiring territory (like occupation, accretion, cession, and prescription) are still relevant, newly emerged states primarily acquire sovereignty through principles rooted in self-determination and state succession.

Traditional Modes (Briefly Relevant):

1. Occupation: Effective control over terra nullius (territory belonging to no one). This is largely obsolete as most land is now under sovereign control.
2. Accretion: Gradual increase of land due to natural causes (e.g., river deposits).
3. Cession: Transfer of territory from one state to another, usually by treaty (e.g., sale or exchange).
4. Prescription: Acquisition of territory through long-term, undisputed exercise of sovereignty by one state over territory formally belonging to another.
5. Conquest: Acquisition of territory by force. This mode is now largely illegal under modern international law, particularly after the UN Charter's prohibition on the use of force.

Principles for Newly Emerged States: Newly emerged states typically acquire territorial sovereignty through processes that emphasize self-determination and the legal framework of state succession:

1. Self-Determination: This is a fundamental principle of international law, particularly enshrined in the UN Charter and various UN resolutions. It asserts the right of peoples to freely determine their political status and pursue their economic, social, and cultural development. For newly emerged states, this often means the right of a colonial people to gain independence and establish their own state within the boundaries of the former colonial territory. The exercise of self-determination leads to the creation of a new sovereign entity with control over its territory.

2. State Succession: When a new state emerges from an existing one (e.g., through decolonization, dissolution, or secession), the question arises of how rights and obligations, including territorial boundaries, are transferred. The principle of state succession governs this. For newly independent states, the general rule is that they succeed to the boundaries of the former colonial or parent state. This is often guided by the principle of uti possidetis juris.

3. Uti Possidetis Juris: This Latin phrase means 'as you possess under law.' It is a crucial principle in the context of newly independent states, particularly in post-colonial Africa and Latin America. It dictates that newly formed sovereign states should retain the internal administrative borders that existed during their colonial or pre-independence period as their international boundaries. The primary purpose of uti possidetis juris is to prevent disputes and maintain stability by avoiding a vacuum of sovereignty and potential border conflicts that could arise from newly independent states attempting to redraw boundaries. This principle effectively 'freezes' the existing administrative boundaries into international frontiers.

4. Recognition: While not a mode of acquisition itself, recognition by other states is a practical and political necessity for a newly emerged state to fully exercise its territorial sovereignty on the international stage. Recognition confirms the new state's existence and its control over its territory, facilitating diplomatic relations and international cooperation.

In essence, newly emerged states acquire territorial sovereignty primarily through the exercise of the right to self-determination, which is then formalized and stabilized by the principles of state succession and uti possidetis juris, often within the pre-existing administrative boundaries. This process is crucial for establishing their legal identity and territorial integrity in the international system.