Breaking news: Recent and escalating violence in the disputed border region of Abyei threatens to plunge North and South Sudan back into civil war. In a flagrant violation of peace agreements, the Sudanese government invaded Abyei and escalated bombing and aid cut-offs in Darfur.

Satellite images show a buildup of northern Sudanese forces including troops, warplanes and tanks.

Doctors without Borders is reporting a steady flow of refugees fleeing south away from the threat of violence in Abyei. Hungry, thirsty, and scared -- they are arriving in new villages with swollen feet after walking for hours or days. Some are collapsing from exhaustion. 

Abyei has long been disputed --  both Sudan’s north and south claim it as their own. It was the site of numerous massacres until the recent civil war ended in 2005. 

The Obama administration, laudably, has already started taking action and making bold statements to head off escalation and prevent more violence.

But this latest escalation and show of force calls for stronger action. We need the White House to raise the stakes. Ask President Obama to take swift and urgent action now.