Three weeks ago, I visited Darfur with the Conservative international development spokesman, Andrew Mitchell. Even in the short time since we were there, the situation has deteriorated further. El Fasher, the town where we stayed, and the hub of the aid effort, has come under direct threat from the Janjaweed militia. The UN and humanitarian agencies have been forced to evacuate their staff.
That is the depressing backdrop for today's worldwide Day for Darfur.
I saw at first hand how women are among the foremost victims of that conflict. The Janjaweed militia have deliberately chosen rape and sexual violence as weapons in their terrifying campaign of ethnic cleansing.
At the al-Salaam camp, I heard women describe the daily terror they face when they venture outside the camp to collect firewood. They are an easy target for attack, and run the risk of rape, abduction, assault and murder every time they leave the camp.
It is hard to estimate how many women and girls in Darfur have been raped or abused, as they are often shamed into silence. But it is clear that there has been an increase in such attacks since African Union (AU) troops reduced their "firewood patrols" this summer.
The world must act in the face of these horrors. The AU peacekeeping force should resume its regular patrols, while we could help to expand the supply of more efficient stoves, to reduce the need for women to leave camps to gather firewood. But we also need to confront head on the political causes of this humanitarian crisis.
Make no mistake, the Janjaweed militia are doing the dirty work of the regime in Khartoum. A month ago in Addis Ababa, the Sudanese regime led the world to believe it was serious about ending this conflict. The next day, its forces attacked from the air - and the Janjaweed from the ground - the town in Darfur where the next round of peace talks were to take place.
The world has been patient beyond measure with Khartoum. It is time for a tougher approach. We must insist on a robust peacekeeping force and an indefinite extension of the AU mandate beyond June 2007. The force should be bolstered with expertise and equipment from UN and individual governments. Peacekeeping troops should be given a specific mandate to use all necessary means to defend civilians.
We must work hard to get a political process back on track. But, above all, we must make clear to the individuals at the top of the regime that their actions will bring consequences. Britain should support the freezing of the assets abroad of key Sudanese leaders, and travel bans against them. The International Criminal Court must be strongly encouraged to pursue its criminal investigations with the utmost vigour.
Today is - ironically - International Human Rights Day. It will have a hollow ring in the camps of Darfur. We owe it to the people I saw in those camps a month ago to speak up - and act - on their behalf.