The animosity between the Persian Gulf’s leading oil producers is nothing new, but the latest secret exchanges are yet another clear sign that the conservative ruling al-Saud family in Riyadh has no intention of mending ties with its powerful Shia Muslim neighbour.

Already, Saudi-Iran relations are such that they appear to be affecting not only oil markets but regional stability.

The Saudi paranoia over Tehran’s influence has been on the increase since the accession to the throne of new King Salman in January after the death of his brother, King Abdullah.

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