Middle East

Qatar crisis: The deep diplomatic tensions behind the row

Sometimes the recipe for a dispute says "leave to simmer". This one has been simmering for years. But then suddenly some of the cooks increase the heat substantially and dispute boils over into full-blown crisis.

The underlying tensions between Qatar and three of her Gulf neighbours in particular have been visible for two decades. This is a region largely of absolute monarchs - kings or emirs - who have in common a very firm grip on politics at home, to head off any dissent which could represent a threat to their individual regime survival.

But the emir of Qatar pursues a series of policies which simply don't fit into the rigid orthodoxy expected by most of the others, notably Saudi Arabia, the superpower of Sunni Islam.

His unconventional foreign policy is seen as a threat to Sunni solidarity, particularly because the emir and his ministers promote dialogue and a search for good relations with the rival regional superpower, Shia Muslim Iran.