Following reunification of Vietnam, the Hoa bore the brunt of socialist transformation in the South. The control and regulation of markets was one of the most sensitive and persistent problems faced by the government following the beginning of North–South integration in 1975. The government, in its doctrinaire efforts to communize the commercial, market-oriented Southern economy, faced several paradoxes. The first was the need both to cultivate and to control commercial activity by ethnic Chinese in the South, especially in Ho Chi Minh City (formerly Saigon). Chinese businesses controlled much of the economic activity in Ho Chi Minh City and South Vietnam. 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 March 24 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 countryside 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.