January 2, 1993 - The international mediators Cyrus Vance and Lord Owen unveiled a plan to divide Bosnia up into 10 provinces, mostly along ethnic lines. The plan was accepted by the Bosnian government but was rejected by the Bosnian Serbs.
March, 1993 - Fights broke out between Bosnian Croats and Muslims over the roughly 30% of Bosnia not already in Serb hands.
March 31, 1993 - UN Security Council Resolution 816 extended the ban to cover all flights not authorized by UNPROFOR and authorized member states to take all necessary measures, in event of further violations, to ensure compliance with the ban. The NAC approved NATO's plans for the enforcement of the ban on 8 April 1993 and notified the UN of their willingness to undertake the operation. NATO Operation Deny Flight began at noon GMT on Monday, 12 April 1993 with aircraft from France, the Netherlands and the United States. At a NATO Foreign Ministers meeting on 10 June 1993, in response to UN Security Council Resolution Resolution 836, it was agreed NATO would provide protective air power in case of attacks against UNPROFOR in Bosnia-Herzegovina. This led to the deployment of CAS aircraft to the Southern Region. These forces have been providing cover for UNPROFOR since 22 July 1993.
April/May, 1993 - During April and May, the UN Security Council declared six "safe areas" for Bosnian Muslims: Sarajevo, Tuzla, Bihac, Srebrenica, Zepa and Gorazde.
April 12, 1993 - NATO begins combat patrols with fighters from France, the Netherlands and United States, over Bosnia to enforce compliance with UN ban on flights, in Operation Deny Flight.
April 14, 1993 - Bosnian, Croate and Muslim troops fight in central Bosnia.
April 20, 1993 - Two fighter aircraft patrolling the no-fly zone in Operation Deny Flight investigated a radar contact near Banja Luka. The contact landed before visual identification could be performed.
April 22, 1993 - Six NATO fighter aircraft patrolling the no-fly zone over Bosnia-Herzegovina in Operation Deny Flight investigated three radar contacts.
The first radar contact (noted 1428GMT) was investigated by two Dutch F-16s but the aircraft landed before visual identification could be performed. The other two contacts could also not be visually identified.
April 25, 1993 - NATO fighter aircraft patrolling the no- fly zone investigated three radar contacts. Two Dutch F-16s were vectored to the first contact at 0759GMT. The other contacts were also investigated by Dutch F-16s.
April 27, 1993 - A Dutch F-16 noted a slow moving radar contact at 0532GMT, which was confirmed by a second Dutch F-16. There was no positive identification. The second radar contact was also investigated by Dutch F-16s at 0747GMT with a similar result.
April 28, 1993 - NAEW controllers vectored a Dutch F-16 to a radar contact, but visual identification could not be established.
May 1, 1993 - Two NATO F-15 fighters detected a radar contact near Gorazde, which could be identified as a helicopter. The helicopter was escorted until it had left the no-fly zone. A second helicopter was also escorted by a NATO F-15 flight.
May 6, 1993 - The Bosnian-Serb "parliament" rejected the plans for peace for the third time, despite pressure of Serb president Milosevic. The Security Council declared the areas of Sarajevo, Tuzla, Zepa, Gorazde, and Bihac as "safe areas". Previously, Srebrenica had been declared a "safe area".
May 25, 1993 - The Security Council announced the establishment of an international tribunal for war criminals from ex-Yugoslavia.
June 1993 - NATO offers close air support to UN troops and other personnel in Bosnia if they are attacked and request air strikes.
July 31, 1993 - The peace plan of Owen and Stoltenberg to establish a "Union of Republics of Bosnia and Herzegovina" was being accepted at first, but on September 1, 1993, the muslims and Serbs would reject the plan after all.
August 2, 1993 - The North Atlantic Council decided to make immediate preparations for stronger measures, including air strikes, against those responsible for the strangulation of Sarajevo and other areas in Bosnia-Herzegovina, and for wide-scale interference with humanitarian assistance.
These air strikes would be carried out within the framework of the relevant UN Security Council Resolutions, including 770, 776 and 836, and in support of UNPROFOR as it carried out its overall mandate.
At their meeting of 9 August 1993 the NAC approved the military planning for air strikes options in support of humanitarian relief efforts and stood ready to implement them. It further decided to maintain a close review of the situation on the ground in Bosnia-Herzegovina and to re-convene at short notice to decide whether to implement air strikes in coordination with the UN.
December 17, 1993 - Croation and Serb authorities agreed on a ceasefire until January 15, 1994.