Gatekeeper

The CIA has a problem. One of its senior members - an Assistant Deputy Director of Intelligence (ADDI) - is suspected of being involved in drug trafficking. The Assistant Inspector General of the CIA cannot use his own staff to investigate out of fear that the ADDI will be alerted. He also must keep the whole matter contained because he does not know how many other people are involved, or at what level in the intelligence and security services drug use has penetrated.
So, he gets his son Mark Taylor, with the assistance of the DEA, to follow the ADDI on a trip to Afghanistan to find the truth.
That mission proves to be deadly for some, and Mark himself becomes the target. The story involves the Russian Foreign Intelligence Service who are trying to protect a mole in the US, the British MI6 who will not commit to what they know, and the US FBI who have an agent on the case.
In the complex world of the intelligence and security services the actions of a few has a major impact on the personal lives of the major players.