Available in For Your Eyes Only by Ian Fleming, 1960.
It's rumored this 40-page story will provide the inspiration for the next James Bond film starring Daniel Craig. In it, Bond is enlisted in Britain's drug war when M asks him to meet a CIA double-agent named Kristatos. Kristatos tells Bond the man behind the flow of drugs into Britain is an Italian, Enrico Colombo. Further, Kristatos asks Bond to kill Colombo. Bond says he will, if Colombo tries to kill him.
To learn more about Colombo, Bond poses as a thriller writer researching drug-smuggling. As usual, he is distracted by a woman, in this case the blond Viennese Lisl Baum, and captured by the enemy. Surprisingly, Colombo admits he is a smuggler but says Kristatos is the real mastermind, in league with the Russians. The heart of the story is in Bond's decision who to believe.
It takes a while to get comfortable with Fleming in the short form, but if a burst of Bond is what you're looking for, his writing is superior to any posthumous continuation of the character. Here is a Bond who questions the Secret Service's role in the drug war, who prefers efficient operations to "adventurous" ones.