King Faisal Assassination
Saudi Arabia
1975, Mar 25
King Faisal and other Arab leaders protested against the West's support that Israel received from the West through an Oil Embargo.
The King's 30 year old nephew assassinated the king in public. Whatever the nephew's motives were, the country quickly because a close ally with the US in the region.
Sources
Prince recalls US threats against S. Arabia: 1973 oil embargo by Arab, Muslim countries
https://www.dawn.com/news/301370/prince-recalls-us-threats-against-s-arabia-1973-oil-embargo-by-arab-muslim-countries
Books
The House of Saud: The Rise and Rule of the Most Powerful Dynasty in the Arab World
by David Holden
Sleeping with the Devil: How Washington Sold Our Soul For Saudi Crude
by Robert Baer
King Faisal with Nixon