Conversation so far:
What was John O.
Brennan's career?
CIA.
What did he do as CIA?
he was CIA station chief in Riyadh, Saudi Arabia.
What was his career highlights?
On January 7, 2013, Brennan was nominated by President Barack Obama to be director of the Central Intelligence Agency.
Are there any other interesting aspects about this article?
Brennan then left government service for a few years, becoming Chairman of the Intelligence and National Security Alliance (INSA.

Question: How long was he chairman?
Self-contained rewrite: How long was John O. Brennan chairman of the Intelligence and National Security Alliance (INSA)?