Zimbabwe's economic meltdown and political repression just keep accelerating. Four million Zimbabweans have now fled the country, and most of the 8 million remaining there face extreme hardship.

Since 1994, average life expectancy in the beleaguered nation has plummeted from 57 years to 34 years for women, and from 54 years to 37 years for men - the shortest lifespans in the world.

And small wonder. Some 3,500 people die every week from the combined effects of HIV/AIDS, poverty and malnutrition. State-sponsored killings and torture of the opposition activists are common as well. More people die in Zimbabwe every week than in Afghanistan, Darfur or Iraq.

Clearly, African leaders - most notably South African President Thabo Mbeki - have failed the people of Zimbabwe. Yet, as the crisis worsens, there is hope that a new regional leadership will address Africa's forgotten tragedy more forcefully. The United States, too, must reconsider its past policy toward Zimbabwe and seize this new opportunity.

None can fault past U.S. policy, which has featured tough rhetoric and sustained effort to coax the world to act by embracing targeted sanctions. But it's time to change course.

Change in Zimbabwe has always required a healthy dose of reality. There has never been a time like the present to call for a tightening of the noose on the Mugabe regime. The time is now ripe for one simple reason: President Thabo Mbeki of South Africa is heading for the door.

For years, the U.S. State Department has found it way too convenient to "support without reservation" Mr. Mbeki's leadership in resolving the crisis in Zimbabwe. With Mr. Mbeki's departure, State should now admit his "quiet diplomacy" was an unmitigated failure.

Mr. Mbeki's inaction and cavalier attitude to the suffering of the Zimbabwean people has done grave harm to the idea of an "African Renaissance." One can't help but wonder if he ever actually intended to do anything to end the cruelties of Robert Mugabe's reign in Harare.

There is good reason to hope Mr. Mbeki's replacement, the newly elected African National Congress leader Jacob Zuma, understands the calamity that is unfolding to his north and is willing to take the steps necessary to wake the region from the nightmare that Zimbabwe has become.

For one thing, Mr. Zuma's election would have been impossible without the support of South Africa's powerful trade unions that have close and friendly ties with Zimbabwe's opposition Movement for Democratic Change (MDC).

Meanwhile, Washington can do more too. Admittedly, direct U.S. national interest in Zimbabwe is limited, but we can do more to relieve one of the world's greatest humanitarian disasters than simply voice hollow rhetoric.

The time has come to break away from the Mbeki-led talks between the ruling ZANU-PF (Zimbabwe African National Union-Patriotic Front) and the opposition MDC. These talks will never produce a way out of Zimbabwe's political crisis. The talks already are melting down as the MDC sees clearly that Mr. Mugabe does not intend to follow through on reforms that would guarantee free and fair presidential and parliamentary elections in March.

The United States should engage Mr. Zuma and, importantly, the new National Executive Council of the ANC, in discussions on how to create a six-month road map that can lead Zimbabwe through constitutional reforms and toward competitive and internationally monitored elections.

And now that the long-suffering MDC looks set to finally reunite, the White House should invite their presidential candidate, Morgan Tsvangirai, for an Oval Office meeting with President Bush in the next month or so. Mr. Bush is said to be keen to do more about the Zimbabwean crisis. An Oval Office meeting would give Mr. Tsvangirai much-needed international recognition and greater clout at home.

Washington also needs to prepare for a post-Mugabe Zimbabwe. The State Department would do well to intensify its contacts with the opposition.

But long-term planning offers little solace to the suffering people of Zimbabwe. Left alone, the 83-year old dictator will likely outlast many of the hungry and poverty-ridden Zimbabweans he holds captive.

The U.S. can play a more constructive role on Zimbabwe and help it find a way to freedom by publicly and expeditiously parting with the moribund "quiet diplomacy" of Thabo Mbeki.

Tom Woods is a senior associate fellow at the Heritage Foundation and a former deputy assistant secretary of state for Africa. Roger Bate is a resident fellow at the American Enterprise Institute. Marian L. Tupy is a policy analyst at the Cato Institute's Center for Global Liberty and Prosperity.