Sakugama Okiri

 was the last president of the United Nations before the organization was disbanded. He is mentioned in an article found on a terminal at the Capitol Post building.

Quotes
"It is a sad day for the United States. Sadder still for the world. An era of relative peace and prosperity has come to a tragic end. The Resources Wars are upon us, and in my humble opinion the United Nations is needed now more than ever. Sadly, the world disagrees."

Appearances
 is mentioned in Fallout 3 but does not actually appear in the game.