Any day now, the International Criminal Court will issue an arrest warrant for Sudanese President Omar Bashir. In preparation, Sudanese Government troops are massing outside of a town in south Darfur.

The only thing standing between 20,000 civilians and the government troops are 196 lightly armed UN/AU peacekeepers.

I know people’s eyes sometimes glaze over when they see some combination of the terms “humanitarian catastrophe in Darfur.” But there is real urgency to what is unfolding. It could easily turn into a blood bath in the coming days--which in turn can call into question the credibility of the entire UN/AU peacekeeping effort in Darfur.

Here’s the backstory: Muhajiriya is a town in south Dafur which is located at a strategic crossroads that connects some of western Sudan’s main thoroughfares. Until Wednesday the town was held by a Darfur rebel group called the Justice and Equality Movement (JEM). The UN, though, negotiated the withdrawal of JEM forces from the town (which were, in any case, no match against the government forces.) By securing the JEM withdrawal, the UN took away the government’s ostensible reason for sacking the town. The peacekeeping mission, UNAMID, is now trying to negotiate a no-fire zone around Muhajiriya.

There is a ticking time bomb, though. In the coming days, the International Criminal Court is expected to issue an arrest warrant for Sudanese president Omar al Bashir. When this happens, the town--peacekeepers, civilians and all--may come under attack. The Sudanese troops outside of Muhajiriya are essentially holding 20,000 people in the town hostage; if the ICC warrant comes, the hammer will drop.

This is an incredibly tense situation. UN Ambassador Susan Rice had strong words for the Sudanese government yesterday. But advocacy groups like the Enough Project are warning that unless the United States sends Khartoum the clear message that reprisal attacks will not be tolerated, a Srebrenica like situation may unfold.

I agree. 20,000 lives hang in the balance.