What was the result of america withdrew from south vietnam

There were many reults from the withdrawal of the US forces:
1) Vietnam was unites under communist rule, and essentially 'terror' was used by these dictators to keep control of the people
2) Vietnam leaned towards the developing nation's, as aid from the Democratic nation's were cut off, and economy did not grow quickly
3) trade barriers led to slow economic growth
Hope this helps

c. businesses/firms & government

there are many answers to this question, such as a diplomat, ambassador, soldier, united nations employee, cia, etc.