The Mekong River lies within the development strategy of the countries sharing the river. However, the advantages of each country on this issue are different, so it can be dominated and controlled by the country with more advantages.

Loose Commitment Among Mekong Countries Prevents Stronger Actions to Prevent Mekong’s Erosion
From the actual study of the impact of the Mekong River water sources on Vietnam's national security, the research team raised a number of issues in international cooperation to ensure the security of Mekong River water sources for Vietnam as follows:
First, The fact that MRC addressed the relationship between countries sharing the Mekong River to strengthen the cooperation between MRC and dialogue partners, development partners have shown international relations in issue of Mekong River needs to be expanded beyond the four MRC member countries. 
This is explained that the MRC only fulfilling its goals with the consensus of two upstream countries is China and Myanmar. Therefore, promoting cooperation with these two countries is essential.
Secondly, the explanation for strengthening control of water resources management in the Mekong River is that exploiting benefits from the Mekong River according to the advantages of each country is an inevitable trend. 
Therefore, the Mekong River lies within the development strategy of the countries sharing the river. However, the advantages of each country on this issue are different, so it can be dominated and controlled by the country with more advantages. 
For China, it is estimated that by 2025 and 2030, China will have a shortage of fresh water and electric power. Therefore, exploiting water resources and hydropower potential from the Mekong River is one of the top priorities for China to overcome this. 
Moreover, with the advantage of geography, the Mekong River part of China has created favorable conditions for China to reach a great deal of benefits in international relations with the Mekong subregion countries.
In fact, China has actively participated in GMS and moved from a dialogue partner to an MRC supervisor. In this way, China is taking full advantage of all the mechanisms to achieve its benefits: both achieving economic benefits and not being constrained to ensure water security, while governing the countries involved through these mechanisms.
China participates in the GMS so that it will not be considered regarding the issue of flow because this mechanism only focuses on trade issues between countries and infrastructure development; China participating as a MRC observer so it will also not considered for the flow of the Mekong because China is not a member. 
With policies and practical actions over time, China has restricted the ability of MRC to operate and turned the control of water resources in this river into a "weapon" to threaten national security of the remaining countries. China even announced that it had reached an agreement with Thailand, Laos and Myanmar to strengthen waterway transport in the dialogue outside the MRC framework.
For Laos, it will benefit greatly when hydropower dams are operated. Laos can export electricity abroad, while increasing irrigation and agricultural productivity in some areas, improving the capacity of larger vessels. For Thailand, there will also be an opportunity to solve energy problems for economic development, improve circulation conditions for large vessels. 
For Cambodia, completed hydropower dam projects will increase economic resources, expand irrigation and labor productivity in some areas. For Vietnam, the country at the bottom of the Mekong River basin is also the only country without hydropower on the mainstream of the Mekong River, and has been affected by climate change, causing sea level rise to create two "pincers" with strong impacts on Vietnam. 
Therefore, in addressing the Mekong River problem contributing to ensuring national security, Vietnam has the most disadvantages and suffers the most losses.
Thirdly, the research results show that the effectiveness of international cooperation on the water resources of the Mekong River in the past time is limited, even though it has just stopped at the political statements. 
The fact that Laos built the Xayabury hydropower dam despite opposition from MRC members has set a bad precedent for cooperation on this issue. This is explained by the great benefits that Laos receives when implementing this project. 
According to a report by the Institute of Sustainable Solutions at Portland University, USA in collaboration with Mae Fah Luang University, Thailand, for all the scenarios for developing the Mekong River basin and Laos are always the countries with the most benefits compared with other countries in the MRC.
One important reason for this is that the PNPCA mechanism is still lax and non-binding. With the Notice and Prior Consultation process, the Agreement only requires the parties to Notify and Consult in advance of the mainstream dam project with a period of 6 months that whether the agreement is reached or not, the consultee will still proceed with the construction. 
This mechanism does not bind members to reach agreement, the previously consulted country does not have the veto to request a stop. In fact, over the past time, the MRC Joint Committee continuously has to extend the previous Consultation period so that MRC and its member countries fully evaluate the impacts and study measures to minimize environmental impacts of the projects.
This regular extension may cause stress and rift in the MRC for the countries proposing the projects states that member countries do not support or prevent the economic development of their country. Therefore, it is necessary to revise and increase the time for the Prior Consultation, both to ensure the time for full evaluation of impacts and to provide solutions to minimize the environmental impact of the projects, while ensuring diplomatic and solidarity srequirements in the region.
This is one part of the reseach paper named “Security for Water Source of Mekong River and Impacts on Vietnam National Security” written by Le Van Thang, Nguyen Hai Thanh, Nguyen Van Tuan.