A short ORG primer on this issue, which opens with:
Climate change is likely to remain the major factor behind water insecurity over the coming decades.... a number of ‘virtual’ factors, ranging from industrial-scale production to perceptions of scarcity, may also contribute to water conflicts in the near to mid-term.
Link:http://www.oxfordresearchgroup.org.u...rtual_problems

It also cites a US NIC report:
During the next 10 years, water problems will contribute to instability in states important to US national security interests. Water shortages, poor water quality, and floods by themselves are unlikely to result in state failure. However, water problems – when combined with poverty, social tensions, environmental degradation, ineffectual leadership, and weak political institutions – contribute to social disruptions that can result in state failure.