This tension was exacerbated by Lebanon’s role in the Arab-Israeli conflict from 1948. Lebanon took in Palestinian refugees; and Palestine Liberation Organisation (PLO) fighters launched operations against Israel from Lebanese territory, prompting Israeli attacks which led to the country's military invasion in 1982 and several attacks afterwards, mainly in 1998 and 2006.

A civil war was sparked in 1975 by a right-wing militant attack that killed 27 Palestinians. The war involved secular leftists, right wing Christian militias, the PLO, Muslim and Druze fighters, Syria, Israel, and their proxies. Syrian troops entered Lebanon in 1976 and dominated its policies untill 2005 when prominent Sunni Prime Minister Rafic Hariri was assassinated; and Israel invaded as well, prompting the deployment of a UN peacekeeping force.

The Ta’if Agreement ended the conflict after 14 years, which left 200,000 dead and more than 17,000 missing. Many have still not been found. Widespread disarmament did not include the Shi’ite Hezbollah militia, who fought against Israel and regained control of South Lebanon. Further conflict took place in 2006 in an Israeli war that affected all of Lebanon's infrastructure.

The Syrian civil war has now caused an influx of 1.5 million Syrian refugees into Lebanon, putting further pressure on already fragile institutions. Syrian tensions have also caused deadly clashes between Sunni Muslims and Alawites loyal to the Syrian government in Northern Lebanon, while Hezbollah forces have also entered Syria fighting alongside the Assad regime forces.

Parliamentary elections were expected to be held in 2017, after parliament extended its own term by four years in 2014. However, these were delayed once more and are now scheduled for 2018.