PM's instruction to contact man in Kabul, fellow having disappeared (9)
I believe the answer is:
callaghan
'pm's' is the definition.
(James Callaghan, UK prime minister 1976-1979)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for callaghan that I've seen before include "Former prime minister" , "3's Labour predecessor" , "Former PM" .)