The invasion of the town of Abyei by the Sudan Armed Forces followed contested reports claiming that a United Nations-escorted convoy was attacked by the forces of the Sudan People's Liberation Army in Dokura on 19 May 2011. On 20 May 2011, the nearby towns of Todach and Tajalei came under artillery fire from SAF forces. In addition, the Sudan Armed Forces also closed roads in and out of Abyei. On 21 March 2012, General Mohamed Atta, director of Sudan’s National Intelligence and Security Services claimed that a force of Sudan People’s Liberation Army - North and Justice and Equality Movement troops attacked the town of Heglig. On 26 March, clashes occurred between SAF and SPLA forces near the border at Teshwin. Fighting continued with confirmed reports of SAF aircraft bombing SPLA positions near the border. The conflicts in Abyei and Heglig were analyzed using multiple high-resolution satellite images. Analysis looked for signs of impending military hostility. These signs included the build up of troops, expansion of infrastructure, and changes in residential patterns. Sites were selected based on media reports, knowledge of existing force deployments, and the locations of key pieces of infrastructure. This work formed part of a project on studying border conflict made possible by a grant from the United States Institute of Peace. Read more at www.aaas.org/geotech/borders.