In the Constitution of India, promotion of international peace and security is mentioned in the—

The promotion of international peace and security is explicitly mentioned in Article 51 of the Constitution of India, which is part of the Directive Principles of State Policy (DPSP) [c1][t2]. Article 51 directs the State to endeavor to promote international peace and security, maintain just and honorable relations between nations, foster respect for international law and treaty obligations, and encourage the settlement of international disputes by arbitration [c1][t5]. These principles are enumerated in Part IV of the Constitution, covering Articles 36 to 51 [c3][t4]. While the Preamble sets the general objectives of the Constitution and Fundamental Duties (Article 51A) outline the obligations of citizens, the specific mandate for the State regarding international peace is categorized under the DPSP framework [t1][t2]. The Ninth Schedule, conversely, deals with the validation of certain Acts and Regulations and is unrelated to foreign policy objectives [c2].

Sources

1. [1] Indian Polity, M. Laxmikanth(7th ed.) > Chapter 88: Foreign Policy > D I Promotion of World Peace > p. 608
2. [2] https://www.indiacode.nic.in/bitstream/123456789/16124/1/the_constitution_of_india.pdf
3. [3] Indian Polity, M. Laxmikanth(7th ed.) > Chapter 9: Directive Principles of State Policy > Directive Principles of State Policy > p. 108
4. [4] https://www.mea.gov.in/images/pdf1/part4.pdf
5. [5] Introduction to the Constitution of India, D. D. Basu (26th ed.). > Chapter 35: TABLES > THE CONSTITUTION AMENDMENT ACTS > p. 519