A the risk of incurring a "feckwa" from Sir Bob, I have always been sceptical about celebrities and the Africa bandwagon. But, all credit should go to actress Mia Farrow. A fortnight ago she embarked on a hunger strike as "an expression of personal outrage" at the world's abandonment of Darfur. Yesterday, on the advice of her doctor, she quit. Now Richard Branson has taken up the baton.

On 4 March, the Sudanese President, Omar al-Bashir, was indicted by the International Criminal Court for crimes against humanity and war crimes. Within days, he expelled 16 aid agencies from Darfur. Over the past six years, an estimated 450,000 people have been slaughtered and some four million displaced, all of them now dependent on aid, without which they face imminent death by starvation and disease. Even now, as we enter the final chapter of the Darfur genocide, the UN blindly pursues its deadly policy of appeasement. Instead of standing up to the bullies in Khartoum, the UN despatched an envoy to seek permission for aid agencies to be readmitted. Unsurprisingly, talks ended in failure.

Meanwhile, Bashir, who dismisses the humanitarian crisis as a Zionist conspiracy, has offered to plug the gap left by expelled NGOs. Despite the fact that this amounts to putting the fox in charge of the hen house, the UN is going along with it. The beleaguered souls in the camps are now prepared to die of hunger, rather than accept "aid" from Khartoum.

The handling of this crisis has been marred by missed opportunities and diplomatic ineptitude. In 2005, the international community unanimously signed up to the "Responsibility to Protect" mandate. This requires them to intervene, by any means necessary, to protect civilians being persecuted by their sovereign state. It has never been implemented in Darfur.

As the peace deal in Southern Sudan collapses, due to Khartoum's failure to honour its commitments there, peace deals are still being championed as the panacea in Darfur. This plays into the hands of the Khartoum government, which will exploit the fact that some rebel groups refuse to play the peace deal game again. Why? Answer: Khartoum is not a credible partner in peace. In 2004, it signed an agreement in which it undertook to disarm the Janjaweed militia and enforce a no-fly zone to prevent bombs being dropped on African villages in Darfur. Neither has happened.

In December 2007, the deployment of a 26,000 strong UN and African Union force was agreed, but 16 months later only 9,000 troops have been mobilised. In total, 16 UN resolutions have been passed, none of which have been implemented, with no consequences for Khartoum.

The time wasted in brokering deals has prolonged the agony on the ground. It is unconscionable to ask Darfuris to negotiate with a government whose President is wanted by the ICC for crimes against humanity. Further talks are futile until Khartoum is made to obey previous deals.

The urgency for action has never been greater, yet the world's media acts as if Darfur has been "solved". The chief criterion for securing coverage, it seems, is celebrity endorsement. Mia Farrow knew this, and so does Richard Branson. Yet she is sneered at for not being prepared to die for her cause, and doubtless he will be mocked when he goes back to food after three days. Silence and inaction kill just as surely as an AK-47. So does diversionary press sneering. How shameful.

Tess Finch-Lees is a human rights campaigner and freelance writer