In The Daily News of Zimbabwe readers could follow the long, cheerless saga of President Robert Mugabe's slide into dictatorship. But the most telling illustration of Zimbabwe's decline is the case of the newspaper itself. The four-year-old daily, the only one not controlled by the government, has been bombed twice, its staff and distributors beaten and harassed, its founding editor driven into exile. Now the government has closed the paper, using undemocratic laws to extinguish one of the last embers of free speech in Zimbabwe.

Mr. Mugabe's current assault on the country's most popular newspaper is built around a 2002 law that compels media to register. The government has used the law to bring charges against or deny accreditation to critical journalists. The Daily News argued that the requirement was unconstitutional and refused to register. On Sept. 11, the Supreme Court ruled that if the newspaper wanted to challenge the media law, it had to register first. Last week the paper did — and it was promptly denied a license to operate. It is now appealing to the courts, but it is unlikely to be successful in a justice system controlled by Mr. Mugabe.

In 23 years as president, Mr. Mugabe has gone from independence hero to tyrant. Zimbabweans now go hungry, in part because his policy of confiscating white-owned farms has led to food shortages. The once-strong economy is near collapse. Mr. Mugabe rigged his own re-election last year, and courts are now prosecuting Morgan Tsvangirai, the leader of the democratic opposition, for treason — a charge that can carry the death penalty.

So far, the near-united opposition of the outside world has had no effect. But one reason is that the nation with the most influence has not joined in. Although South Africa has leverage — it controls Zimbabwe's electric power, for one thing — President Thabo Mbeki argues that diplomacy is more effective than sanctions. Mr. Mbeki, who refuses to criticize a fellow hero of Africa's liberation struggles, should reconsider. The collapse of Zimbabwe is affecting all southern Africa. For the good of the entire region, Mr. Mugabe must step down.