CHINA will soon release statistics showing it has passed Japan as the biggest holder of foreign currency the world has ever seen. Its reserves already exceed $800 billion and are on track to reach $1 trillion by the end of the year, up from just under $4 billion in 1989.

But China, it turns out, has held a similar position before.

History offers parallels to the yawning United States trade deficit and the resulting accumulation of dollars in China. China sells to American companies almost six times as much as it buys, but this is not the first time China has been an export powerhouse. Ancient Rome, for example, found that it had little except glass that China wanted to buy. Pliny complained about the eastward flow of Roman gold along the Silk Road in exchange for Chinese silk.

Long-distance trade collapsed during the early years of the Dark Ages. But through the next several periods of rapid growth in international commerce — from A.D. 600 to 750, from 1000 to 1300 and from 1500 to 1800 — China again tended to run very large trade surpluses. By 1700, Europe was paying with silver for as much as four-fifths of Europe's imports from China because China was interested in little that Europe manufactured.