US authorities linked Iran to a plot to kill the Saudi ambassador to the US. Few contests have defined the modern Middle East like that between Saudi Arabia and the Islamic Republic of Iran.
A longstanding regional rivalry lies behind the web of conspiracies that US authorities on Tuesday said linked Iranian agents to a plot to kill the Saudi Arabia ambassador in Washington.
Few contests have defined the modern Middle East like that between petroleum power Saudi Arabia, ethnically Arab and Sunni Muslim, and the Islamic Republic of Iran, which is ethnically Persian and Shiite Muslim.
The Shiite-Sunni divide stretches back 14 centuries; the conflict between the Persian Empire and its Arab neighbors many centuries before that.
But the modern incarnation of the regional struggle casts Iran as leader of an anti-US, anti-Israeli "Axis of Resistance" that includes Syria and backs Hezbollah in Lebanon and Hamas in the Gaza Strip.
The Saudi camp is more pro-Western, includes rich Persian Gulf monarchies, and backs Fatah in the West Bank and has posited a peace plan that would accept the Israeli state if it withdrew to 1967 borders.