Ethiopia initially tried to persuade Sudan to turn over the suspects through bilateral negotiations, but turned to the OAU after Sudan denied any official involvement. After OAU overtures were also resisted, Ethiopia took the matter to the UN Security Council. Egypt, a newly elected non-permanent member of the Council, pursued the matter actively after it joined the Council in 1996. Following Sudan's refusal to cooperate with investigations or turn over suspects to Ethiopia, diplomatic and travel sanctions were imposed in UNSCR 1054 (26 April 1996).
Coerce government of Sudan to hand over three suspects in the attempted assassination (it is unclear that all of the suspects were in the Sudan, but there is evidence that they entered Ethiopia from the Sudan).
Signal support for the norm against state-sponsored terrorism.
Diplomatic sanctions (reduce the number and level of staff at Sudanese diplomatic missions and control the movement of those remaining, travel restrictions on Sudanese government officials and armed forces).
Sanctions imposition deliberately delayed by 2 weeks. No Sanctions Committee or sanctions monitoring mechanism in place. Enforcement authorities not specified.
Sudan apparently made some efforts to locate suspects and to investigate immigration records in response to OAU investigation prior to the imposition of UNSCR 1044 (January 1996), but did not cooperate thereafter (indicating that it could not fulfill an impossible request), hence UNSCR 1054 (April 1996) imposing diplomatic sanctions; suspects never handed over and some evidence that one fled with Bin Laden to Afghanistan in May 1996.
OAU mediation efforts appear to have been more significant; diplomatic sanctions were largely a nuisance for Sudan.
Norms against state-sponsored terrorism and in support of initiatives taken by regional organizations articulated, but only modest stigmatization (due to Egyptian toning down of sanctions content of UNSCR 1054, which was criticized by the US).
UNSCRs were not the only source of stigmatization, but the ongoing OAU efforts.
No unintended consequences of sanctions observed.