Zimbabwe's presidential elections, set for June 27, are speeding toward a horrific crash.

President Robert G. Mugabe, 84, lost the first round in March to opposition leader Morgan Tsvangerai. Mr. Mugabe didn't accept that the challenger had won, claiming improbably that he had not achieved the 50-percent-plus-one necessary for victory, even though Mr. Tsvangerai's party won the parliamentary elections. A candidate from Mr. Mugabe's own ZANU-PF party also ran to draw votes from Mr. Tsvangerai.

Now, as the runoff between the top two draws near, Mr. Mugabe has turned up the heat on his suffering people to obtain the results he wants, to prolong his 28-year rule of the former Rhodesia. He has instructed the country's army to work for his victory. His supporters and security forces are interfering with Mr. Tsvangerai's campaign, and Mr. Mugabe has said he won't let his opponent take power if he were to win.

In the meantime, the disaster that Mr. Mugabe's rule has wreaked on the economy has not only put an estimated one-fourth of the country at risk of starvation, but also propelled floods of citizens to flee into neighboring South Africa.

Their quest for food, shelter and jobs, in competition with poor South Africans and immigrants from other countries, has led to disorder, rioting and killing, which South Africa has found difficult to control.

Meanwhile, African leaders have stood by mute and impotent. Some have tried to put responsibility on the back of South African President Thabo Mbeki, who has declined to act. South Africa could start by closing its border with Zimbabwe, although it is questionable that Mr. Mugabe would take notice.

Other leaders such as U.N. Secretary-General Ban Ki-moon and British Prime Minister Gordon Brown want to send a U.N. human rights representative and election observers to Zimbabwe -- truly pointless gestures.

Given that Mr. Mugabe has stated that he won't accept the election results unless he wins, and that the situation in Zimbabwe has become increasingly catastrophic in its impact on the southern African region, drastic measures are needed.

Just as Tanzania used its military in 1979 to get rid of Ugandan despot Idi Amin, the countries of southern Africa would be justified in taking decisive military action to get rid of Mr. Mugabe. It is hard to imagine that Zimbabweans would resist them, particularly if they moved in fast, quickly held free and internationally supervised elections and then got out.