Following the reunification of Vietnam, The ethnic Hoa in South Vietnam suffered most from the socialist transformation. A major challenge for the government was how to regulate and control sensitive market activity, especially in Ho Chi Minh City, where Chinese-owned businesses dominated much of the commercial economy. Following Vietnam’s break with China in 1978, some Vietnamese leaders evidently feared the potential for espionage activities within the Chinese business community. On the one hand, Chinese-owned concerns controlled trade in a number of goods and services, such as pharmaceuticals, fertilizer distribution, grain milling, and foreign-currency exchange, that were supposed to be state monopolies. On the other hand, savvy Chinese entrepreneurs provided excellent access to markets for Vietnamese exports through Hong Kong and Singapore. This access became increasingly important in the 1980s as a way of circumventing the boycott on trade with Vietnam imposed by a number of Asian and Western Nations. An announcement on 24 March outlawed all wholesale trade and large business activities, which forced around 30,000 businesses to close down overnight, followed up by another that banned all private trade. Further government policies forced former owners to become farmers in the NEZ or join the armed forces and fight at the Vietnam-Cambodia border and confiscated all old and foreign currencies, as well as any Vietnamese currency in excess of the US value of $250 for urban households and $150 by rural households.