1. Core Legal Answer & Context: State succession refers to the replacement of one state by another in the responsibility for the international relations of territory. It is a complex area of international law dealing with the legal consequences when one state ceases to exist or loses control over territory, and another state takes its place. This can occur through decolonization, unification, dissolution, secession, or transfer of territory.

Theories of State Succession:

• Universal Succession (Old Theory): Posited that the successor state automatically inherited all rights and obligations of the predecessor. Largely discredited due to its inflexibility.
• Partial Succession (Modern Approach - Clean Slate/Tabula Rasa): Favored by newly independent states, suggesting the successor state starts with a 'clean slate,' not automatically bound by predecessor's treaties or obligations, though often tempered by practical considerations.
• Continuity/Identity Theory: Argues that the state's identity continues despite changes in government or territory, implying continuation of rights and obligations. More applicable to changes in government rather than complete replacement.
• Moving Treaty-Frontier Rule: When territory is transferred, the treaties of the predecessor cease to apply to that territory, and those of the successor begin to apply.

Rights and Obligations Arising from State Succession:

• Treaties: Political treaties generally do not transfer. Multilateral treaties of a humanitarian character or those establishing territorial regimes (e.g., boundaries) often continue. Bilateral treaties usually terminate unless expressly agreed otherwise. The 'clean slate' principle often applies to newly independent states.
• Public Property: Generally passes to the successor state, including state archives, public funds, and immovable property.
• Public Debts: A complex area; often, a portion of the public debt is transferred to the successor state, especially if incurred for the benefit of the transferred territory, applying principles of equitable apportionment.
• Nationality: Inhabitants' nationality usually changes to that of the successor state, though options for retaining the old nationality may exist.
• Membership in International Organizations: Not automatically transferred; the successor state typically applies for new membership.
• Private Rights: Generally respected by the successor state, including acquired rights and concessions.

2. Relevant Statutes and Sections:

• Vienna Convention on Succession of States in Respect of Treaties (1978): Codifies rules for treaty succession, establishing the 'clean slate' rule for newly independent states (Article 16) and continuity for boundary and other territorial regimes (Articles 11, 12).
• Vienna Convention on Succession of States in Respect of State Property, Archives and Debts (1983): Though not widely ratified, it reflects customary international law principles regarding the passing of state property and equitable apportionment of debts.
• Customary International Law: Many aspects of state succession are governed by customary international law due to limited ratification of the conventions.

3. Important Landmark Cases:

• Island of Palmas Case (Netherlands v. United States, 1928): Established principles of territorial sovereignty and continuous display of state authority, relevant for determining predecessor's rights over territory.
• Certain Phosphate Lands in Nauru (Nauru v. Australia, 1993): Touched upon the succession of international obligations, particularly concerning trusteeship agreements and environmental responsibilities, highlighting complexities in attributing responsibility after changes in state status.

4. Clear Conclusion: State succession is a critical area of international law governing the transfer of rights and obligations from one state to another concerning territory. While older theories favored universal succession, modern international law, reflected in the Vienna Conventions and customary practice, adopts a more nuanced approach. This often involves a 'clean slate' for newly independent states regarding treaties, while generally ensuring the continuity of territorial regimes and the transfer of public property, with equitable apportionment of debts. The specific rights and obligations transferred depend heavily on the nature of the succession event and specific agreements between the states involved.