Conversation so far:
when did he start CIA?
DCI Smith recruited Dulles to oversee the agency's covert operations as Deputy Director for Plans, a position he held from January 4, 1951.
what did he do in the CIA?
Dulles was promoted to Deputy Director of Central Intelligence, second in the intelligence hierarchy.

Question: what did he do?
Self-contained rewrite: What did Allen Dulles do?