Despite having water agreements with India, the Himalayan states of Nepal and Bhutan, unfortunately, receive an unequal share of their mountainous water resources. Water-sharing is a complex problem. It needs a logical solution for its equitable distribution. However, it is often difficult for the most amiable border nations to reach a unanimously agreed water-sharing formula for regulating their transboundary water reserves. South Asian countries have signed various water treaties to resolve their water disputes. Yet, in most cases under these treaties, the dispute resolution mechanisms are either not fully evolved, like Ganges Water Treaty, or demand full implementation of all the clauses of the treaties in true letter and spirit, like the Indus Water Treaty (IWT). Water in South Asia is a source of both conflict and cooperation. One example of cooperation in the region is the IWT 1960 signed between Pakistan and India, which shows riparian cooperation. The treaty has survived two major wars. Since water is a politically charged and emotive issue, it is subject to various interpretations and disputes. In this regard, there is a conflict over the shared water resources between Pakistan and India such as the former claims that the latter manipulated the treaty in its favour. Islamabad has shown its concerns that Delhi has moved far away from its obligation and has been twisting the clauses and violating the IWT, which hampers its implementation. India’s large-scale diversions by constructing dams in violation of the IWT have far-reaching consequences for socio-economic growth and national politics regarding water distribution within the provinces in Pakistan. Another case from South Asia is the co-operative water agreement between Bangladesh and India, in which the former has been in constant strife with the latter to receive its agreed share. Although the Ganges Water Treaty, signed in 1996, was initially considered major progress by the political regimes of both countries, the treaty failed to address or resolve all bilateral disputes of the Ganges’ waters. The treaty is considered “imperfect” by the political realists in Bangladesh. Dhaka has been protesting against the violation of GWT by India. Various allegations and suspicions continue to fuel criticism of the treaty by the Bangladesh Nationalist Party and have created tensions in their bilateral relationship. The nature of water conflict between Bangladesh and India is of high conflict and low cooperation dynamic because unlike the IWT, there is no dispute resolution mechanism. Unlike Bangladesh, the nature of water conflict between India and Nepal is of high conflict and high cooperation – given exploitation and interference by India for obtaining Nepal’s water resources – which has led to strong disagreement over the precise definition of the clauses of their co-operative water treaty. For instance, the age-old disagreement persists in India and Nepal over the interpretation of the Sugauli Treaty signed in 1816 between Nepal and British East India Company, which delineated the frontier along the River Maha Kali in Nepal. Islamabad has shown its concerns that Delhi has moved far away from its obligation and has been twisting the clauses and violating the IWT, which hampers its implementation In 1997, when Nepal planned to work out a treaty on hydroelectric development of the river, the Indo-Nepal rift deepened when both failed to decide which stream constituted the source of the river. Nepal considers the Limpiyadhura as the source stream, while India claims Lipu Lekh to be the source stream. Nepal wants to utilise its water resources for generating electricity, which is not only necessary to meet its energy demand, but also to generate revenue while exporting energy to other South Asian countries. However, its wish to export electricity and develop hydro projects is also tied to India’s will, due to its border blockade by India. On the contrary, the water dynamic between India and Bhutan is one of the low conflicts and low cooperation. Resultantly, both countries have little interaction between them over shared water resources. Although Bhutan has the highest per capita annual water availability in South Asia, the country is facing the internal challenge of water accessibility. Households across the country face drinking water issues. Bhutan also needs water storage capacity, which is subject to its lower riparian, i.e. India’s will. In this context, despite having water agreements with India, the Himalayan states of Nepal and Bhutan, unfortunately, receive an unequal share of their mountainous water resources. India, a low riparian state, uses upper riparian privileges while influencing and dictating the water projects of these two landlocked mountainous states. Thus, the water issues between the co-riparian countries of the region remain ‘a potential casus belli.’ In a nutshell, the existing channels of dialogue, bilateral agreements and dispute resolution mechanisms, require that the South Asian countries display firm commitment in fulfilling the requirements of existing water agreements; cooperate with its riparian states on water; maintain an ecological and biodiversity balance; discard unilateral actions on run-of-the-rivers and restrict itself in constructing massive hydro projects/dams. Only then, the possibility of water conflict turning into a full-fledged war could be avoided. If they do not act accordingly and continuously violates the sensitivity of South Asian water cooperative regimes, water could likely become a threat to regional security. The writer is a research officer at the Islamabad Policy Research Institute