How did the iranian revolution in 1979 play a major role in the diplomatic relationship between the united states and saudi arabia?
a) saudi arabia was a major ally with iran, so they distanced themselves diplomatically from the u. s.
b) the united states and saudi arabia grew closer diplomatically due to the oil industry in the area.
c) the united states and saudi arabia overthrew the revolutionary government of iran the following year.
d) iran threatened to invade saudi arabia, but due to solid iran-u. s. diplomacy the invasion never happened.

The correct answer is B) The United States and Saudi Arabia grew closer diplomatically due to the oil industry in the area.

Saudi Arabia is the oldest ally of the United States in the Middle East. Their alliance can be traced back to 1933, when President Franklin D. Roosevelt and King Ibn Al-Saud accorded that Saudi Arabia would grant access to the US to Saudi oil sources, in exchange for American support to the Saudi regime.

Since 1953, Iran was also an important ally to the US. The monarchic dictatorship of the Shah Pahlavi counted with the favor of the US government since it worked like a brake for Iranian nationalism that seeks to nationalize the oil industry.

The Iranian Revolution in 1979 overthrown the Iranian monarchic government and established a Shia Islamic regime which was strongly anti-American, it nationalized the Iranian oil industry, and it wanted to expand its influence in the Middle East, disputing the position of Saudi Arabia. The new Iran became a natural enemy of Saudi Arabia, which is a Sunni kingdom and a regional leader, and also it became an enemy of the US.

For these reasons, the US and Saudi Arabia strengthened their diplomatic relations in order to face the Iranian threat.