A fascinating paper  has been published by Maria J. Stephan and Erica Chenoweth (HT to Rose Marie Berger  writing for Sojourners in the US) on how nonviolence seems more successful than violent strategies in challenging regimes.
We have long suggested that we need greater investment in, and exploration of, these kinds of strategies. Prior to the invasion of Iraq in 2002 suggested on Radio 4 and elsewhere  that such possibilities were worth considering.
The findings of the new study challenge the conventional wisdom that violent resistance against conventionally superior adversaries is the most effective way for resistance groups to achieve policy goals.
The authors assert that nonviolent resistance is a forceful alternative to political violence that can pose effective challenges to democratic and nondemocratic opponents, and at times can do so more effectively than violent resistance.
They point out that from 2000 to 2006, organised civilian populations successfully employed nonviolent methods including boycotts, strikes, protests, and organised noncooperation to challenge entrenched power and exact political concessions in Serbia (2000), Madagascar (2002), Georgia (2003) and Ukraine (2004–05), Lebanon (2005), and Nepal (2006).
This is what the authors say:
"Our findings show that major nonviolent campaigns have achieved success 53 per cent of the time, compared with 26 per cent for violent resistance campaigns.
"There are two reasons for this success. First, a campaign’s commitment to nonviolent methods enhances its domestic and international legitimacy and encourages more broad-based participation in the resistance, which translates into increased pressure being brought to bear on the target. Recognition of the challenge group’s grievances can translate into greater internal and external support for that group and alienation of the target regime, undermining the regime’s main sources of political, economic, and even military power.
"Second, whereas governments easily justify violent counterattacks against armed insurgents, regime violence against nonviolent movements is more likely to backfire against the regime. Potentially sympathetic publics perceive violent militants as having maximalist or extremist goals beyond accommodation, but they perceive nonviolent resistance groups as less extreme, thereby enhancing their appeal and facilitating the extraction of concessions through bargaining."
The full paper: 'Why civil resistance works' can be found here: http://www.mitpressjournals.org/doi/pdf/10.1162/isec.2008.33.1.7