United Nations Security Council resolution 1559, adopted on 2 September 2004, after recalling resolutions 425 (1978), 426 (1978), 520 (1982) and 1553 (2004) on the situation in Lebanon, the Council supported free and fair presidential elections in Lebanon, urging the Lebanese government to establish control over its territory, disarm militias like Hezbollah, and facilitate the withdrawal of any remaining foreign forces from the country.

Nine countries voted in favor: Angola, Benin, Chile, France, Germany, Romania, Spain, the United Kingdom, and the United States. Six countries abstained: Algeria, Brazil, China, Pakistan, the Philippines and Russia.

The resolution was sponsored by France and the United States. The cooperation between these two nations on an issue concerning the Middle East was seen as a significant improvement in their relationship, compared to their earlier bitter disagreement over the 2003 invasion of Iraq. Because Lebanon was governed by France as a League of Nations mandate 1919–1943, France has long taken a special interest in Lebanon.

It called on Lebanon to establish its sovereignty over all of its territory and called on Syria as a foreign force to withdraw from Lebanon and to cease intervening in the internal politics of Lebanon. The resolution also called on all Lebanese and foreign forces on Lebanese soil to disband and declared support for a "free and fair electoral process".

The resolution was coauthored by France and the United States. Echoing the Taif Agreement, the resolution "calls upon all remaining foreign forces to withdraw from Lebanon" and "for the disbanding and disarmament of all Lebanese and non-Lebanese militias." Lebanon has requested that Israel withdraw from the disputed Shebaa Farms and the hills of Kfar-Shouba and return the Lebanese detainees in Israel as a condition for fully implementing Resolution 1559 which includes disbanding of the military wing of Hezbollah. Critics of the resolution argue however that an attempt from the weak and politically divided Lebanese army to disarm Hezbollah would be very difficult and could restart the Lebanese civil war. Syria was also in violation of the resolution until recently because of their military presence in Lebanon.

On 7 October 2004, the UN Secretary General Kofi Annan reported to the Security Council regarding the lack of compliance with Resolution 1559. Mr. Annan concluded his report by saying: "It is time, 14 years after the end of hostilities and four years after the Israeli withdrawal from Lebanon, for all parties concerned to set aside the remaining vestiges of the past. The withdrawal of foreign forces and the disbandment and disarmament of militias would, with finality, end that sad chapter of Lebanese history."

The 20 January 2005 UN Secretary-General's report on Lebanon stated that "The continually asserted position of the Government of Lebanon that the Blue Line is not valid in the Shab'a farms area is not compatible with Security Council resolutions. The Council has recognized the Blue Line as valid for purposes of confirming Israel’s withdrawal pursuant to resolution 425 (1978). The UN Security Council has repeatedly requested that all parties respect the Blue Line in its entirety."

On 28 January 2005, Resolution 1583 called upon the Government of Lebanon to fully extend and exercise its sole and effective authority throughout the south, including through the deployment of sufficient numbers of Lebanese armed and security forces, to ensure a calm environment throughout the area, including along the Blue Line, and to exert control over the use of force on its territory and from it.