evidence: The president of Djibouti, Ismail Omar Guelleh, addressed the Council on 19 May and asserted that the Eritrean occupation of his country’s territory was a matter of the gravest national security concern and warned that recent meetings between Eritrean officials and Ambassador Heller was not a sign that Eritrea was becoming more cooperative. [...] Djibouti sent a letter to the Council expressing concern about a build-up of Eritrean troops along the common border. Recalling previous tensions in 1996 over border issues, the letter contained a timeline of the build-up starting in February up until April 2008, when Djibouti President Ismael Omar Guelleh advised of Eritrean occupation of the Ras-Doumeira border area.