The four main rivers in question are shown here, in green for where they flow in Pakistan, and in blue in India

THE GEOGRAPHY

The Indus River originates in the Tibetan plateau, making its 3,200km journey southwards along the entire length of Pakistan, before emptying into the Arabian Sea. The river basin is divided between Pakistan, which has about 60 per cent of the catchment area, India with about 20 per cent, Afghanistan with 5 per cent and around 15 per cent in Tibet. The two major riparians, Pakistan and India have extensively dammed the Indus River to provide for irrigation and hydro-electricity. [A riparian zone is defined as the area of interface between land and a river or stream.]

The Indus has five main tributaries. The Jhelum, the largest of these, originates in the Valley of Kashmir. The Chenab, a second tributary, flows through the Jammu region of the state of Jammu and Kashmir before entering the Indian state of Punjab. The remaining three tributaries (Ravi, Sutlej and Beas) either originate or flow through India's state of Himachal before entering Indian Punjab.

As a result, if the Line of Control (LoC) between India and Pakistan in Kashmir, were to move from being a defacto to a recognised international border, India would permanently become the upper riparian and Pakistan the lower riparian of the Indus River and all of its tributaries.

The Indus is a river system that sustains communities in both India and Pakistan. In Pakistan, it is the only river system supporting the country, where more than 92 per cent of the land is arid or semi-arid. In India, it is one of two main river systems supporting the country's northwest: Punjab, Haryana and Rajasthan (generally considered to be water deficient areas).

Given that over half of Pakistan's population is employed in the agricultural sector and that Punjab produces more than 20 per cent of India's wheat and is known as the "bread basket" of the Republic of India, the importance of the Indus River to the well-being and economy of both countries cannot be overemphasised.

THE POLITICAL HISTORY

In arbitrating the border between India and Pakistan in 1947, Sir Cyril Radcliffe, the chairman of the bodies set up to demarcate the borders, was unable to decide what to do with the Indus River system, given that it was likely to be vital to both states.

The biggest problem, of course, lay with the partitioning of the state of Punjab, as it contained a complex irrigation system built by the British to be run under a single administration. The task was eventually delegated to the Chief Engineers of East Punjab (India) and West Punjab (Pakistan) who agreed to allow the existing water sharing systems to continue until the following year. This Standstill Agreement between India and Pakistan expired on March 31, 1948. On the following day Indian Punjab cut off water flow to Pakistan.

The conflict in Kashmir overlapped with the water disputes, and by January 1948 India had taken the Kashmir issue to the United Nations Security Council (UNSC). On April 21, 1948, a resolution calling for a ceasefire and withdrawal of all troops was passed.

The Kashmir dispute and disputes over the sharing of water resources are intertwined. From independence to the present day, they remain the two biggest challenges when it comes to normalising relations between the states of India and Pakistan.

Later in 1948, Eugene Black, then president of the World Bank, offered the services of his organisation to help negotiate a solution to the water-sharing dispute between the two countries. Although India was not eager to allow third-party involvement, both countries eventually agreed to this proposal.

Evidence and records from the time suggest that in 1948, when the Kashmir issue was taken to the UNSC and the canal dispute between East and West Punjab first arose (in April of that year), they were treated as distinctly separate political and economic issues.

In the early days of independence, the fact that India was able to shut off the Central Bari Doab Canals at the time of the sowing season, causing significant damage to Pakistan's crops, exposed a central weakness and vulnerability in the newly created state that was desperately trying to establish its independence.

As noted by one British general on a visit to the area in 1948, the dispute centres around the "water insecur[ity]" of Pakistan, as all of its rivers either originate in or pass through India.

Experts agreed, saying that resolving water disputes under the auspices of the World Bank was "one way to reduce hostility" over Kashmir.

Nevertheless, military and political clashes over Kashmir in the early years of independence appear to be more about ideology and sovereignity, rather than sharing water resources. A communique from the British High Commissioner's office in Karachi, then capital of Pakistan, from November 1951 seems to suggest otherwise, however:

"But one assumption they have refused to entertain: that India should have control over Kashmir. By having such control India could ruin Pakistan, simply by refusing to operate Mangla at the headworks. It is almost certain therefore that Pakistan would reject any solution of the Kashmir problem which would give these powers; she would rather embark on a war which she fully understood to be suicidal."

Indian ministers at the time were also issuing statements, saying that controlling the entire flow of the Indus river would be impossible, "even if India controlled Kashmir".

It would appear that somewhere along the ideological path, as negotiations on water were being held, politicians worked out that a resolution to the water dispute may well directly influence the Kashmir problem.

Indeed some experts have suggested that Pakistan thought that it could solve the Kashmir dispute through solving canal-related issues, but India completely denied this route of resolution.

Consequently, the Indus Water Treaty was signed by both countries in September 1960, giving exclusive rights over the three western rivers of the Indus river system (Jhelum, Chenab and Indus) to Pakistan, and over the three eastern rivers (Sutlej, Ravi and Beas) to India.

The signing of the treaty and the financing of various water storage projects to benefit Pakistan and India meant that tensions were minimal and to a great degree much of Kashmir's water importance was forgotten for the next couple of decades.

As the populations of both countries increased exponentially, however, water resources came under increasing stress. With India preparing ambitious irrigation project plans, it was possible to see how, by the 1990s, Kashmir's hydrological importance had once again become a serious issue.

PAKISTAN'S POSITION

The fact that, unlike India, all of Pakistan is wholly dependent upon the Indus River system is a geographical reality.

Another reality that compounds this one is the fact that, as the upstream riparian on all five of the main Indus tributaries that flow into Pakistan, India has the strategically advantageous position with regards to control and flow of water.

John Briscoe, a subcontinental water expert, former World Bank senior water expert and currently a professor at Harvard University, recognised Pakistan's unhappy position in the following words: "This is a very uneven playing field. The regional hegemon is the upper riparian and has all the cards in its hands."

Pakistan is all too aware of its vulnerable position vis-a-vis water and the fact that more than half of independent Pakistan's time has been spent under military rule has not helped to de-escalate or 'de-securitise' the water discourse in the country.

Over the years, water has been raised as an issue directly linked to Kashmir. Pakistan's political leaders and military elites have emphasised that if they are forced to let go of their claim to Kashmir, that will mean letting go of the source of Jhelum and Chenab as well and being at the mercy of India for water.

Though it is unrealistic to assume that India could readily and easily violate the terms of the Indus Water Treaty, Briscoe emphasises that Pakistan and India do not have "normal, trustful relations". The trust deficit along with the fact that India once blocked water flows to Pakistan has the military establishment convinced that they must hold on to their claim to Kashmir in an effort to maintain the country's water security.

Interestingly enough, another Pakistani organisation that has been vociferous in defending Pakistan's rights over Kashmir and criticising India's "aggression" against Pakistan through reduced water flows is the 'charity' Jammat-ud-Dawa (JuD). The JuD is widely believed to be a front group of the militant outfit Lashkar-e-Taiba (LeT) that has been linked to the Mumbai attacks of 2008. Though there is widespread conjecture on the organisation's close association with Pakistan's intelligence agencies, officially, such a relationship has always been denied.

It is worth noting that the JuD has publicly declared India's "occupation" of Kashmir unacceptable and has also termed its policy of blocking water to Pakistan a justification to wage jihad. In most public statements, however, the JuD tends not to link water and Kashmir, in contrast to the Pakistani military's position on the argument.

INDIA'S POSITION

India has consistently and emphatically maintained that it has never meddled with Pakistan's share of the Indus waters.

Even as the Indus Water Treaty was being negotiated, with the Indian government assuring Pakistan and the World Bank that water was not being blocked, Chintamanrao Deshmukh, the then Indian finance minister, stated in a 1953 parliamentary address that the serious food shortage in Pakistan was not a result of India blocking river flows.

"Even if it were assumed that some mistakes were made at some short period, which in any case did not exceed one or two weeks," he said.

Throughout the history of the dispute, India has rarely, if ever, acknowledged that it has tampered with the supply of water flowing into Pakistan. Since there is also a large amount of secrecy that surrounds the governance of the Indus waters and data is not readily shared, there is no definitive way to prove whether India has just got caught up in Pakistani sensationalism or whether the seeds of resentment and securitisation of water were sowed and are being maintained by the Indian side.

In negotiations and meetings with Pakistani counterparts on the wider Indo-Pak relationship, India does not deal with water and Kashmir as the same issue. In fact, it has often been suggested by analysts that a more consolidated agreement on water might perhaps be a more readily achievable goal in India-Pakistan composite dialogue as compared to Kashmir.

Briscoe finds that the Indian press seems to have a uniform view on water issues, in relation to Pakistan. He says that it was explained to him as follows: "When it comes to Kashmir - and the Indus Treaty is considered an integral part of Kashmir" - the ministry of external affairs (India's foreign ministry) instructs the media about what they are allowed to say. In certain cases, India is happy to conflate the Kashmir and water issues, whereas in negotiations with Pakistan it would like to deal with them as distinct and separate.

Currently, India is in the process of building a number of dams on the Jhelum and Chenab Rivers (both of which originate in Kashmir), such as the Kishenganga, Dal Huste, Sawalkot etc. The Indus Water Treaty allows India to harness the hydropower potential of the Jhelum and Chenab Rivers, as long as it does not reduce or delay the supply to Pakistan. India therefore maintains that its projects are in compliance with the treaty and sees no conflict with Pakistan on these issues.

KASHMIR'S POSITION

The region of Kashmir sees itself losing considerably from the Indus Water Treaty because it is not allowed to fully exploit the hydropower potential of its own rivers.

In June 2011, a Chinese news agency reported that the state government of Kashmir was looking for reputed multi-national consultancies to calculate the exact loss to Kashmir from the Indus Water Treaty so that the government will have a number it can take to the Indian federal government.

Given that both Pakistan and India are dangerously energy and water starved and nowhere close to an agreement on Kashmir, teamed with the impact of climate change and population pressures, the prognosis on the Indo-Pak water problem involving Kashmir is anything but positive.