On 27 June 2011, the Security Council authorized the deployment of a peacekeeping force to the disputed Abyei Area, which straddles northern and southern Sudan and has been claimed by both sides. The Council’s action came in response to the renewed violence, escalating tensions and population displacement in the Abyei region as Southern Sudan was preparing to formally declare its independence from the Sudan on 9 July 2011 — the culmination of a comprehensive 2005 peace agreement. Resource rich Abyei had in the weeks prior to the Security Council decision been the scene of deadly clashes that drove more than 100,000 people from their homes.
With the unanimous adoption of resolution 1990 (2011), the Council formally established, for six months, the United Nations Interim Security Force for Abyei (UNISFA), which would comprise a maximum of 4,200 military personnel*, 50 police personnel and appropriate civilian support. Authorizing the use of force to protect civilians and humanitarian workers in Abyei, the Council underscored the need for UNISFA’s quick deployment and urged Secretary-General Ban Ki-moon “to take necessary steps to ensure rapid and effective implementation” of the resolution.
The new operation answered the call for speedy Council action in the wake of the agreement reached on 20 June between the Sudanese Government and the Sudan People’s Liberation Movement (SPLM) to withdraw their respective forces and allow Ethiopian peacekeepers in Abyei (the so-called ‘Temporary Arrangements for the Administration and Security of the Abyei Area’). Under that deal, brokered by former South African President Thabo Mbeki, the two sides agreed on the need for a third party to monitor the flashpoint border between north and south.
*On 29 May 2013, the Security Council, by its resolution 2104, increased UNISFA’s military strength up to 5,326 peacekeepers, as requested by Sudan and South Sudan on 8 March 2013.