The Asian Development Bank estimated that South-East Asia will require $3.1 trillion between 2016 and 2030 to develop energy, transportation, water and sanitation systems for sustainable development. Most of that investment is required in lower-income countries, such as Cambodia and Laos.
That critical need for major infrastructure investment has created an opportunity for China to engage in “infrastructure diplomacy”. Beijing has almost fully exploited all of the hydropower potential in its portion of the Mekong River. It is lending support to downstream countries in South-East Asia to develop their own hydropower facilities.
It has been proven that Chinese dams can have a dramatic effect on water levels in the lower Mekong basin. That could give Beijing additional leverage over the region. China is now in a position to build goodwill with the countries of the lower Mekong basin through infrastructure development or use its dams to coerce its near neighbours into accepting Chinese strategic interests. Both options are likely to be detrimental to the US and the broader Western world.
In full: http://www.futuredirections.org.au/publication/chinese-intentions-towards-the-mekong-river-and-mainland-south-east-asia/