Warring parties and international aid providers in Sudan have an historic opportunity to bring to an end what is perhaps the most extreme and long-running example in the world of using access to humanitarian aid as an instrument of war. A mid-December meeting between the UN and Sudan's warring parties- the Technical Committee for Humanitarian Assistance (TCHA)- provides an unparalleled vehicle to build on recent short-term agreements and to once and for all remove the institutional barriers to unimpeded access for humanitarian agencies. Such an opportunity may not arise again, so it is imperative that mediators, the UN Security Council, and interested governments provide concentrated and immediate support for this objective.