James Packard is an agent with the Criminal Warfare Agencies.
The CWA is a fictional organization best described as "Special Branch with license to travel". It can also be called "Interpol With Arrest Powers." Though the headquarters for CWA is in New York, there are branches in other major cities. Packard works for Colonel Forbes, the director of the London bureau.
The CWA got its start with the Committee of Twelve, as they are called, who got together to devise a plan to hold down the advances of the criminal element. The members were a former Supreme Court Justice, an ex-Chief of Police of New York, a former Vice President, a retired Army general, and three leaders of industry joined on one side of the Atlantic with five members from the British Commonwealth.
Packard's job is to seek out criminal activity anywhere in the world and to bring the perpetrators to justice, or at least stop their errant ways. He carries a gun and is more than willing to use it when needed. And he takes his job very, very seriously.
While Packard's work is that of an international policeman, the bad guys often are entrenched in the local governments and his actions have wide spread ramifications.
Note: The books were first published under the penname of Robert Conington Galway but as Philip McCutchan's popularity grew, that pseudonym was dropped.
Note: I have seen several lists of the books in the series and each has had an 11th book named "The Negative Man". I bought a copy and read it. Neither Packard nor the CWA is in the book.