India-Pakistan Relations UPSC Notes: History, Wars, Indus Water Treaty

“At the stroke of the midnight hour, when the world sleeps, India will awake to life and freedom.”

With these words, Jawaharlal Nehru announced not just India’s independence but also the birth of a divided subcontinent. The Partition of 1947 set the stage for a relationship defined by wars, peace talks, and unresolved tensions between India and Pakistan. From the Indus Waters Treaty to modern diplomatic challenges, this story remains central to South Asia’s politics and security.

For UPSC aspirants, understanding India–Pakistan relations is key to mastering GS Paper 2 (IR) and current affairs with historical depth and clarity.

The border between India and Pakistan stretches from the icy peaks of Jammu & Kashmir to the salt marshes of Gujarat’s Rann of Kutch. The total border length is approximately 3,323 km, with a mix of terrains that makes border management one of India’s toughest security challenges. 

Indian States/UTs Sharing Border with Pakistan

1. Jammu & Kashmir (Union Territory)

• Shares the Line of Control (LoC) and International Border with Pakistan-occupied Kashmir and Punjab province.
• Siachen Glacier, Kargil, and Poonch are the sensitive regions: 

2. Punjab

• The most accessible border, with the iconic Wagah–Attari crossing for trade and ceremonies.
• Densely populated; heavy movement of goods and people.
• Security is managed by the Border Security Force (BSF).

3. Rajasthan

• Shares a 1,048 km desert border, partly fenced, partly open.
• Key districts include Barmer, Jaisalmer, Bikaner, and Sri Ganganagar.
• Used during the 1965 and 1971 wars as active battle zones.

4. Gujarat

• Includes the Rann of Kutch and Sir Creek, a disputed maritime boundary.
• Vulnerable due to its marshy terrain and coastal stretch.
• Strategic for coastal surveillance and marine security.

India and Pakistan, two nuclear-armed neighbours in South Asia, share a long and complicated history marked by both conflict and cooperation since their independence in 1947. The partition of British India created India and Pakistan, causing massive violence and forcing millions to flee, leaving deep wounds that still affect their relations today. 

1. Colonial Era and Partition Foundation

• British Colonial Policy of Division: Britain utilised a "divide and rule" strategy. They fuelled communal tensions between the Hindu and Muslim communities to maintain control.
• Muslim League and Separate Statehood: Muhammad Ali Jinnah led the All-India Muslim League's demand for a separate Muslim homeland based on the "Two-Nation Theory".
• Mountbatten Plan (June 3, 1947): The last British Viceroy announced the partition of India to end colonial rule, with independence set for August 14-15, 1947.
• Radcliffe Line: Cyril Radcliffe demarcated contentious borders through Punjab and Bengal based on religious majorities, creating territorial ambiguities.

2. Early India-Pakistan War and the Kashmir Dispute

• First Kashmir War (1947-1948): Maharaja Hari Singh acceded Kashmir to India; fighting ensued until the UN-brokered ceasefire established the Ceasefire Line (CFL).
• Second Indo-Pakistani War (1965): Pakistan's Operation Gibraltar attempted infiltration; full-scale conflict ended with the Tashkent Declaration restoring pre-war positions.
• Third War and Bangladesh Creation (1971): Indian military intervention against Pakistan's crackdown on East Pakistan resulted in Bangladesh's independence.
• Simla Agreement (July 2, 1972): PM Indira Gandhi and President Zulfikar Ali Bhutto signed a bilateral dispute-resolution framework, converting the CFL into the Line of Control (LoC).
• Kargil War (1999): Pakistani military infiltration in the Kargil district led to Indian military victory and US-mediated resolution, reinforcing the LoC as a de facto boundary.

3. Nuclear Dimension and Strategic Escalation

• 1974 Smiling Buddha Operation: India conducted its first nuclear test, declared as "Peaceful Nuclear Explosion," establishing nuclear capability.
• Pokhran-2 Tests (May 1998): India conducted five nuclear detonations under PM Atal Bihari Vajpayee, asserting its status as a full nuclear power.
• Pakistan's Chaghi Tests (May 1998): Pakistan responded with six nuclear tests 17 days after India, officially becoming a declared nuclear power.
• International Condemnation and Sanctions: UN Security Council resolution condemned tests; the United States imposed economic sanctions on both nations.

4. Terrorism

• Major Tension: Pakistan-backed militant groups conduct cross-border attacks.
• Organisations: Lashkar-e-Taiba (LeT), Jaish-e-Mohammed (JeM), Hizbul Mujahideen.

5. Institutional Agreements and Water Sharing

• Indus Waters Treaty (September 19, 1960): Nine-year World Bank-mediated negotiation resulted in a historic water-sharing agreement between PM Nehru and President Ayub Khan.
• Eastern Rivers (India's Control): Sutlej, Ravi, Beas rivers; India receives 20% of the Indus Basin waters.
• Western Rivers (Pakistan's Control): Indus, Chenab, Jhelum rivers; Pakistan receives 80% of the Indus Basin waters.
• Dispute Resolution Mechanism: Permanent Indus Commission established for managing disputes.

6. Strategic and Geopolitical Dimensions

• Line of Control (LoC): 740-kilometre de facto border in Kashmir, heavily militarised with frequent skirmishes, barbed wire fortifications, and regular ceasefire violations.
• Siachen Glacier: Northernmost LoC extension seized by India (Operation Meghdoot, 1984); bone of contention with Pakistan; most casualties from natural disasters.
• Pakistan-Occupied Kashmir (POK) and Gilgit-Baltistan: Pakistani-administered territories; Indian claims over the entire Kashmir region remain unresolved.
• 2019 Article 370 Revocation: India withdrew the special constitutional status of Jammu & Kashmir, intensifying Pakistani diplomatic protests and regional tensions.

7. Cultural Diplomacy and People-to-People Ties

• Shared Historical Heritage: Common linguistic, cultural, and artistic traditions rooted in the pre-partition Indian subcontinent, including Sufi and Bhakti movements.
• Kartarpur Corridor (2019): 4.5 KM stretch enabling Indian Sikh pilgrims visa-free access to Gurdwara Darbar Sahib, symbolising potential people-to-people connectivity.

Also read: Article 370 of the Indian Constitution: 6 Years After Abrogation

Specific geographic regions have been focal points of repeated tensions. These areas represent territorial disputes, military confrontations, and cross-border infiltration routes affecting stability.

1. Kashmir & Line of Control: 

A 740-km military control line dividing Kashmir. It was established after the 1947-48 war; renamed after the 1972 Simla Agreement.

• Indian Side: Jammu & Kashmir (J&K), Ladakh
• Pakistani Side: Pakistan-Occupied Kashmir (PoK), Gilgit-Baltistan.

2. Siachen Glacier Region

1,000 square miles of disputed territory in northern Kashmir.

• Indian Interpretation: The territory extends to the Saltoro Ridge.
• Pakistani interpretation: Territory extends to the Karakoram Pass.

During Operation Meghdoot (1984), India captured a glacier.

3. International Border (Western Border)

Officially recognised border between India and Pakistan (except LoC). The border separates Indian Punjab and Jammu from Pakistani Punjab and Sindh.

4. Jammu & Kashmir (J&K) Hotspots

• Kupwara, Baramulla: Frequent ceasefire violations
• Poonch, Rajouri: Cross-border infiltration areas
• Akhnoor: International border incidents
• Kargil: Site of the 1999 war; strategically important
• Pahalgam: Recent terror attack site (April 2025)

5. Maritime Boundary Issues

• There is a disagreement over the maritime boundary in the Sir Creek region. Oil and gas exploration rights remain contested. The strategic importance of the Arabian Sea affects both nations' interests.

Also read: Kargil Vijay Diwas 2025: Honouring 26 Years of Valour and Victory

Despite persistent conflict, India and Pakistan share interests in water management, regional commerce, and cultural exchange.

1. Indus Waters Treaty (1960):

• Brokered by the World Bank after 9 years of negotiation.
• Governed by the Permanent Indus Commission.
• Water allocation: India gets 20%, Pakistan gets 80% of the Indus system.
• Eastern rivers (Ravi, Beas, Sutlej) are under Indian control.
• Western rivers (Indus, Chenab, Jhelum) are under Pakistani control.

2. Trade & Economic Cooperation:

• Indian Exports: Organic chemicals, pharmaceuticals, sugar, confectionery
• Pakistani Exports: Apparel, salt, sulphur, lime, cement.
• Tariff raised to 200% on Pakistani goods in 2019; MFN status withdrawn.

3. Cultural Diplomacy and People-to-People Ties

• Shared Historical Heritage: Common linguistic, cultural, and artistic traditions rooted in the pre-partition Indian subcontinent, including Sufi and Bhakti movements.
• Kartarpur Corridor (2019): 4.5 Km stretch enabling Indian Sikh pilgrims visa-free access to Gurdwara Darbar Sahib, symbolising potential people-to-people connectivity.

4. Transportation & Connectivity

• Proposed rail and road networks for regional connectivity.
• Wagah border crossing for trade.
• Potential for improved logistics and reduced transportation costs.

5. Cultural & People-to-People Exchange

• Shared Indus Valley Civilisation heritage.
• Common linguistic (Urdu-Hindi), literary, and artistic traditions.
• Potential for student exchanges and educational cooperation.
• Film and entertainment industry linkages.

In 2025, a major terror attack disrupted the fragile peace between India and Pakistan, leading to rising tensions, diplomatic strain, and a major shift in their bilateral relations.

The Pahalgam Terror Attack

On April 22, 2025, militants attacked tourists in Pahalgam, Kashmir, killing 26 people, including 25 Indians and 1 Nepali. The attack targeted Hindu men, and though TRF first claimed responsibility, it later denied involvement, raising doubts about who was behind it.

For India, the attack was a turning point. Prime Minister Modi vowed to hunt down the attackers and warned that there would be no difference between terrorists and their sponsors, directly signalling Pakistan’s responsibility.

Breaking 65 Years of Cooperation

On April 23 2025, India suspended the 65-year-old Indus Waters Treaty, which had survived four wars. This bold move showed India’s readiness to challenge old rules and send a strong message to Pakistan.

Operation Sindoor

From May 7 to 10, 2025, India launched Operation Sindoor, its biggest military action since the 1971 war. The multi-day strikes hit terrorist camps and infrastructure in Pakistan, using BrahMos missiles and advanced precision weapons to show strength and determination.

The message was clear that India would no longer rely only on diplomacy after terror attacks. Operation Sindoor marked a shift toward preemptive action to destroy terror networks before they strike.

India’s approach to India–Pakistan relations must be guided by realism and national interest. Dialogue is important, but only when backed by credible action from Pakistan against terrorism and cross-border hostility. 

India should continue strengthening its defence, deepening global partnerships, and using diplomacy to highlight its commitment to peace and stability. A peaceful relationship is desirable, but never at the cost of India’s sovereignty and security.

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