I am not a student of revolution / violent changes of government and so rely on some history and observing recent events - say back to the fall of the Shah in 1979.

In Tunisia the catalyst appears to have been the student trader's arrest and self-immolation. After several days of nationwide disorder, none of which affected key institutions, there is reporting that the Army commander declined to order troops to use live rounds to quell the disorder. Today the BBC has reported police and para-military police have joined demonstrations.

When does state coercive power, including Information Warfare, cease to have an impact and why? Capability, non-lethal and lethal; lack of will, confidence etc. I do recall the fall of East Germany, the GDR, was attributed to a clear Soviet stance and so without the Soviet "muscle" the GDR was unable to use coercion.

I am uncertain that faraway observers, like me, can discern the tipping point beforehand; leaving aside how often the tipping point occurs and is avoided. Nor that extensive intelligence-gathering and awareness can help.

It puzzles me, how can ruthless states apparently cease to function. Not to overlook that such states can falter and then crush opposition - Tienanmen Square for example.

Talking to Muslims and reading the often cited tipping point into radicalisation, not violence, is a human rights violation that has impact.