The initial wave of public discontent in Bahrain followed the pattern set in other Arab nations: a public alienated from the ruling class demanded reforms and a change in the political status quo.

But as the days passed the protests became more and more sectarian in form. Seventy per cent of the population is Shia, while those who govern the country are exclusively Sunni.
 
And the escalating protests are watched with increasing concern across the King Fahd Causeway in neighbouring Saudi Arabia. 
 
The ruling Sunni monarchy there are suspiciously watching Shia activitity in the region - the spectre of any increased Iranian influence long seen as a threat to Sunni control.
 
The unprecedented decision to send troops and police into another Arab state was publically at least a decision taken by the six members of the Gulf Cooperation Council - justified by the need for stability in these turbulent times.
 
And as the global economy continues to feel the effects of the Japanese earthquake and subsequent nuclear threat, stability wherever possible is what many are looking for.

Is the core of sectarian divide about to be exposed? And could the fallout become regional?

Inside Story, with presenter Mike Hanna, discusses with Abdullah al-Alami, a Saudi Arabian economist and writer; Salman Shaikh, the director of Brookings Centre in Doha; and Nabeel Rajab, the vice-president of the Bahrain Centre for Human Rights.

This episode of Inside Story aired from Tuesday, March 15, 2011.