I need some help tracking a story that I thought I had on the shelf but didn't. Let me outline the plot, and some details I recall really well, I think it was called Trader's Oath but my google search came up empty.
The Plot: a man who is a Trader is sent to a space station in Low Earth Orbit to negotiate a deal with a government official. The problem is the Chipponese, who run the space station and live in orbit, are setting up an operation to grow food on the moon, and that means they won't need Earth anymore, upsetting a delicate balance of power. The trader meets up with the government official's wife who tells him about this project; he has to decide if he is "a human being first and a Trader second" because if he proceeds as ordered it could mean war on Earth.
The world: Earth has suffered war and a lot of destruction, the USSR collapsed (this was written when it still existed). China and Japan went to war and the Chinese got nuked.
The world is divided into several power blocs; one is called the Chipponese, who are the "re-united" Japan and China and have space stations in LEO. (Evidently a giant cloud of radioactive dust forced them to accelerate plans to colonize LEO and the warring nations decided fallout was the greater common threat). Then there are the Americans who grow a lot of food. The Chills are people who live in polar regions and make high-technology products. The traders manage the commerce between them.
Some technologies are Trader Recording Spheres; they are used so traders can keep diaries and logs.
I am pretty sure the story dates from 1987 or so; certainly before 1990 and after 1985.