Apartheid was defeated by the investment sanctions and the refusal of foreign banks to roll over loans.
Defeated is also a misn omer as no-one surrendered - De Klerk and the Nats negotiated a settlement.
The major contribution that mass mobilisation made in the form of the MDM and UDF was to successfully obby these overseas Western governments and lending istritutions.
Trade sanctions were largely by-passed through middle men and sourcing goods via countries like Taiwan and Israel.