The United Nations drew the Blue Line in June 2000 to serve as a boundary between Israel and Lebanon after Israel completed its withdrawal from Southern Lebanon. This event came after a long and contentious history of conflict and occupation, with Israel having maintained a military presence in the region since it invaded Lebanon in 1982 during the Lebanon War. The UN's involvement and the establishment of the Blue Line were seen as crucial steps towards stabilizing the area, which had been fraught with violence and security concerns.

The delineation of the Blue Line was based on Israel's interpretation of the borders established by the United Nations in 1949, following the armistice that ended the first Arab-Israeli conflict. The UN's task was to confirm and clarify that Israel had withdrawn to this line, as stipulated by UN Security Council Resolution 425. The verification process involved extensive monitoring by UN troops and diplomatic engagement with both Israeli and Lebanese authorities to ensure compliance.

The establishment of the Blue Line was intended to symbolize a path towards peace and security in a region marked by historical conflict. The actions taken by the UN included the deployment of the United Nations Interim Force in Lebanon (UNIFIL), which aimed to oversee and maintain peace along the border. This development sought to foster dialogue between both nations and minimize incidents that could trigger military responses, although skirmishes and tensions continued in the years following the border's establishment.