On Friday, the An Yue Jiang, a Chinese ship carrying arms bound for Zimbabwe, left the port of Durban. Earlier, a high court refused to allow the weapons to be transported across South African soil.

The decision capped a surprising turn of events. On Thursday, Themba Maseko, a spokesman for Pretoria, said that his country would not stop the shipment as long as formalities had been completed. Dockers of the South African Transport and Allied Workers Union, however, refused to unload the cargo, fearing that Zimbabwe’s Robert Mugabe might use the weapons against his opponents, who are locked in a post-election standoff with him. Mugabe appears to have lost his post in the March 29 presidential election but is unwilling to step aside.

“This vessel must return to China with the arms on board,” the union said in a statement. Unfortunately, that’s unlikely. The rust bucket is headed for Luanda, where the weapons will be unloaded for a long overland trek to Zimbabwe. So the workers have won only a symbolic victory.

Yet symbolism matters, especially to autocrats. South African workers apparently know that. “How positive it is that ordinary dockers have refused to allow that boat to go further,” said Mary Robinson, the former U.N. high commissioner for human rights. Mary, you’re right, of course. But let’s not call these South Africans “ordinary.” They have done more to stop Chinese autocrats from aiding Mugabe than their own leader, Thabo Mbeki–and than the most powerful individual on earth, President George W. Bush.

As Robinson said, the Durban port workers tried to stop something they believed was wrong. Perhaps the American people should ask their leader to go to South Africa so he can learn a thing or two from the longshoremen in Durban.