The statement that International Law evidences the evidentiary theory of recognition refers to one of the two main theories concerning the legal effects of recognizing a new state or government: the evidentiary (or declaratory) theory and the constitutive theory.

The Evidentiary (Declaratory) Theory of Recognition: This theory posits that the act of recognition by other states is merely a formal acknowledgment of an existing factual situation. In other words, a state or government exists as a matter of international law once it meets the objective criteria for statehood or effective governance, irrespective of whether other states recognize it. Recognition, under this theory, does not create the state or government; it simply declares that the recognizing state accepts the factual existence of the new entity and is willing to enter into relations with it.

Key Aspects of the Evidentiary Theory:

1. Objective Criteria for Statehood: The theory relies on the Montevideo Convention on the Rights and Duties of States (1933), which outlines the traditional criteria for statehood: a permanent population, a defined territory, a government, and the capacity to enter into relations with other states. Once these criteria are met, an entity is considered a state under international law.
2. Legal Personality Pre-exists Recognition: According to this theory, a new state or government acquires international legal personality and rights (e.g., to enter into treaties, to claim territory, to defend itself) as soon as it fulfills the objective criteria, even before it is recognized by other states.
3. Recognition as a Political Act: Recognition is viewed primarily as a political act, signifying the recognizing state's willingness to engage in diplomatic and other relations. It is not a prerequisite for the existence of the recognized entity.
4. Non-Recognition Does Not Invalidate Statehood: If a state meets the objective criteria but is not recognized by some or even many other states, its statehood is not legally invalidated. Non-recognition might limit its practical ability to engage in international relations, but it does not negate its legal existence.

Evidence in International Law Supporting the Evidentiary Theory:

• State Practice: Many states, while often delaying recognition for political reasons, implicitly acknowledge the factual existence of new entities. For instance, states often deal with unrecognized entities on a de facto basis, or their courts may treat the laws of an unrecognized government as valid for private law purposes.
• Judicial Decisions: International courts and tribunals, as well as national courts, have generally leaned towards the declaratory theory. For example, in the Tinoco Arbitration (Great Britain v. Costa Rica, 1923), the arbitrator ruled that the non-recognition of the Tinoco regime by Great Britain did not mean that the regime's acts were invalid under international law. Similarly, the International Court of Justice (ICJ) has often focused on the objective criteria of statehood rather than the act of recognition.
• UN Membership: The process of admission to the United Nations (UN) is often cited. A state applies for membership, and its admission is a collective act of recognition by the international community. However, the entity must already possess the attributes of statehood to be considered for membership.
• Principle of Effectiveness: International law places a strong emphasis on the principle of effectiveness, meaning that a factual situation that is stable and effective tends to generate legal consequences. An effectively established government, even if unrecognized, often exercises sovereign powers that are difficult to ignore.

Contrast with the Constitutive Theory: The constitutive theory, in contrast, argues that recognition is a necessary condition for the existence of a state or government in international law. Without recognition by other states, an entity, even if it meets the objective criteria, does not acquire international legal personality. This theory has largely been discredited due to its impracticality (e.g., how many recognitions are needed? What if some states recognize and others don't?) and its potential to make statehood dependent on political whims rather than objective facts.

Conclusion: Modern international law overwhelmingly supports the evidentiary (declaratory) theory of recognition. While recognition remains a significant political act that facilitates diplomatic relations and international cooperation, it is not a legal prerequisite for statehood or the legal existence of a government. The emphasis is on the objective fulfillment of criteria for statehood, with recognition serving as an acknowledgment of that existing reality. This approach ensures that international law is based on factual effectiveness and objective criteria, rather than the subjective and often politically motivated decisions of individual states.