Examine the tension between the Union's exclusive treaty-making power and states' interests in transboundary river-water agreements, with reference to Bihar's concerns on the Ganga Treaty.

Article 253 empowers Parliament to legislate for implementing any international agreement, making treaty-making an exclusive Union competence [3]. Yet water is a State subject, and riparian states bear the consequences — a tension now visible as the 1996 India–Bangladesh Ganga Treaty nears expiry in December 2026.

The constitutional basis of Union primacy

• Article 253 read with Union List entries on foreign affairs and treaties allows the Centre to conclude and implement river agreements irrespective of State List Entry 17 (water) [3].
• Diplomacy is led by the MEA, with the Ministry of Jal Shakti providing technical inputs; states have an advisory, not a veto, role [1][4].
• This ensures a single national voice abroad and prevents sub-national vetoes from paralysing neighbourhood policy.

Where states' interests press back

• The Treaty shares Ganga flows at Farakka during the lean season (1 January–31 May, on a 10-daily basis), directly affecting upstream and downstream states [2].
• Bihar's grievance: JD(U) has sought renegotiation or non-renewal, citing silt accumulation upstream and risks to drinking, irrigation and industrial supply for the state's population [4].
• West Bengal hosts the barrage and has similarly resisted river deals, as with Teesta — showing the pattern is structural, not partisan.
• Ecological stress — declining flows and climate variability — makes purely legal renewal inadequate without state-level scientific assessment.

Reconciling the two

• Institutionalised consultation: the Jal Shakti-led inter-ministerial and stakeholder consultations before renewal are a workable template [4].
• EAM Jaishankar's assurance that Bihar's interests will be factored in shows political accommodation within Union competence [4].
• A standing Centre–State technical committee, with basin-state representation on the Joint Committee of experts, would embed this permanently [1].

Union exclusivity is a necessity of foreign policy, not a denial of federalism. Cooperative federalism suggests that consultation, transparent data-sharing and state-specific impact studies should precede renewal — securing both India's bilateral commitments and Bihar's water security.