Some countries also have a substantial legal or illegal domestic trade in weapons for use by its citizens.
Baekje continued substantial trade with Goguryeo, and actively adopted Chinese culture and technology.
Economically Wales was very undeveloped, lacking towns or coins and any substantial trade.
Private business and substantial foreign trade only got started under the reforms initiated in the late 1970's by Deng Xiaoping.
The often substantial trade within countries is largely unmeasured.
This grew into a substantial ribbon-making trade early in the 19th century, but declined in the 1830s.
A quick search on the website indicates that there is still a substantial trade among collectors for them.
One of his partners was George Allsopp and they conducted a substantial trade, much of it unlicensed.
Both now have mixed economies and substantial trade with East and West.
In this period there was substantial trade between India and Rome in spices, fabric and gold.