The trend of conventions including clauses that prohibit or limit reservations is a significant development in international law, reflecting a desire for greater uniformity and integrity in treaty regimes. To assess whether this trend hinders the growth of international law, it's essential to understand the role of reservations and the implications of their restriction.

Role of Reservations in Treaty Law: Reservations, as defined by the Vienna Convention on the Law of Treaties (VCLT), are unilateral statements made by a State when signing, ratifying, accepting, approving or acceding to a treaty, whereby it purports to exclude or to modify the legal effect of certain provisions of the treaty in their application to that State. Their primary purpose is to encourage wider participation in multilateral treaties by allowing states to opt out of specific provisions they cannot accept, without rejecting the entire treaty.

Arguments for Reservations (and why their prohibition might hinder growth):

1. Promoting Universality: Reservations are crucial for achieving widespread adherence to multilateral treaties, especially those dealing with sensitive political, economic, or social issues. Without the flexibility to make reservations, many states might choose not to become parties to a treaty, thereby limiting its reach and effectiveness. This could hinder the 'growth' of international law by preventing the establishment of universally accepted norms.
2. Protecting National Sovereignty and Interests: States often have unique constitutional requirements, domestic laws, or national interests that may conflict with certain treaty provisions. Reservations allow them to reconcile these domestic considerations with their international obligations, making treaty ratification politically feasible.
3. Facilitating Compromise: In complex negotiations, the possibility of reservations can help achieve consensus on a treaty text, as states know they can later adjust their commitments to suit their specific circumstances. Prohibiting reservations might lead to protracted negotiations or weaker, less ambitious treaty texts to accommodate all parties from the outset.
4. Evolution of Norms: Sometimes, a reservation might reflect an emerging or dissenting view on a particular norm. While not ideal for the immediate treaty, it can contribute to the dynamic evolution of international law by highlighting areas where consensus is still developing.

Arguments Against Reservations (and why their prohibition might foster growth):

1. Maintaining Treaty Integrity and Object and Purpose: Excessive or broad reservations can undermine the core object and purpose of a treaty, creating a fragmented and inconsistent legal regime. If states can pick and choose which obligations to accept, the treaty's overall coherence and effectiveness are diminished. Prohibiting reservations ensures that all parties commit to the fundamental tenets of the agreement, thereby strengthening the treaty as a source of international law.
2. Ensuring Uniformity and Predictability: When reservations are restricted or prohibited, the legal obligations for all parties are more uniform and predictable. This clarity is vital for the consistent application and enforcement of international law, fostering greater stability in international relations.
3. Preventing Abuse: Some states might use reservations to escape significant obligations, effectively rendering their participation in a treaty meaningless. Clauses prohibiting reservations prevent such abuses and ensure genuine commitment.
4. Strengthening Norms: For treaties codifying fundamental norms (e.g., human rights, humanitarian law), allowing extensive reservations can weaken the universal character of these norms. Prohibiting reservations in such treaties reinforces the idea that certain principles are non-derogable or universally applicable, thus promoting the growth of stronger, more robust international legal norms.

Conclusion: The trend of restricting or prohibiting reservations is not inherently a hindrance to the growth of international law; rather, it represents a shift towards a more robust and integrated international legal order. While reservations historically served to broaden participation, the modern trend reflects a recognition that for certain types of treaties, particularly those establishing fundamental human rights or environmental protection regimes, the integrity and uniformity of obligations are paramount. For these treaties, the growth of international law is better served by ensuring that states commit to the full scope of the agreement, even if it means fewer initial ratifications. The challenge lies in striking a balance: for some treaties, flexibility through reservations remains crucial for universality, while for others, the integrity of the regime demands their restriction. The specific context and nature of the treaty are key determinants in assessing whether such clauses foster or hinder the development of international law.