Negotiations between Russian foreign minister Izvolski and Austria resulted in an agreement on September 16, 1908 at the Buchlau Conference. Russia agreed not to oppose Austria's annexation of Bosnia and Herzegovina; in return, Russia was to have military access to the Straits.
When Austria proclaimed the annexation of Bosnia and Herzegovina on October 6, 1908, Serbia and Montenegro began to mobilize troops. Both countries considered these two provinces to be under their sphere of influence and were unwilling to surrender these claims to Austria. The Russian government, having been uninformed of its foreign minister's arrangements at Buchlau, ordered Izvolski to oppose Austrian actions and support Serbian claims.
As the Serbs continued to arm, Austria was negotiating with several countries to prevent outside support for Serbia. On March 2, 1909, the powers intervened and attempted to convince Serbia to recognized Austrian claims to avoid a war. Nevertheless, a Serbian note to Austria on March 10 failed to recognize the annexation and provoked Austrian ill-will. Serbia lost possible allies, and, when Russia finally responded to German pressure to abandon Serbia on March 22, Serbia realized the futility of its position. On March 31 Serbia recognized Austria's annexation of Bosnia and Herzegovina and the conflict was resolved.