May 12, 2003. Riyadh, Saudi Arabia. Armed al-Qaida terrorists storm the diplomatic compound killing 36 people including nine Americans. The assailants committed suicide by detonating a truck bomb
They did not attack a diplomatic compound, but rather three compounds owned by Western companies.
http://en.wikipedia.org/wiki/Riyadh_compound_bombings March 2, 2006. Karachi, Pakistan again. Suicide bomber attacks the U.S. Consulate killing four people, including U.S. diplomat David Foy who was directly targeted by the attackers.
The suicide bomber did not attack the US Consulate. He detonated himself in the Marriott parking lot next door.
http://www.cnn.com/2006/WORLD/asiapcf/03/01/karachi.blast/ September 17, 2008. Sana’a, Yemen. Terrorists dressed as military officials attack the U.S. Embassy with an arsenal of weapons including RPGs and detonate two car bombs. Sixteen people are killed, including an American student and her husband (they had been married for three weeks when the attack occurred). This is the second attack on this embassy in seven months.
This one they did attack the US Embassy in Yemen (the second time that year). The terrorists were dressed as policemen, not military officials, and 18 people were killed, not 16.
http://en.wikipedia.org/wiki/2008_attack_on_the_American_Embassy_in_Yemen
