UN Security Council's Resolution 242 was agreed unanimously on November 22, 1967, five months after a crushing Israeli offensive during which it occupied vast swathes of Arab territory.
Fifty years ago, the UN Security Council adopted a resolution on an Israeli withdrawal from occupied territories that remains the reference for peace in the Middle East, even though it has never been implemented.
While the resolution lays the foundation for negotiations on the basis of a return of land in exchange for an end to hostilities, the resolution contains a subtle difference in its French and English texts that has instead further soured relations.
The Six-Day war
In June,1967, Israel's army had struck out with lightning speed and occupied 70,000 sq km (27,000 square miles) of Arab land in what became known as the Six-Day War.
Israel took the West Bank and East Jerusalem from Jordan, the Gaza Strip and the Sinai Peninsula from Egypt, and the Syrian Golan Heights. The human losses were also heavy.
That August, Arab nations voiced their anger at a summit in Khartoum remembered for its "Three No's": no negotiation with Israel, no reconciliation and no recognition of the Jewish nation.
Israel believed the areas it had taken were essential to ensure its security, a stance adopted by its US ally after several attacks on Israel from these positions.
The issue of 'the'
The dispute was referred to the United Nations for arbitration, and of the various resolutions proposed to the Security Council, it was a British initiative that was adopted.
Resolution 242 underlines the "inadmissibility of the acquisition of territory by war and the need to work for a just and lasting peace in the Middle East in which every State in the area can live in security."
But there is a single-word difference in the English and French versions of the text that follows, both of them official, which has given rise to divergent interpretations that persist decades down the line.
The English version calls for the withdrawal of Israeli forces "from territories occupied in the recent conflict," without saying which ones.
The French version is more specific, demanding withdrawal "des territoires occupés lors du récent conflit."
The difference is that "des" means "of the", which specifies all the occupied territories. There is no similar "the" in English.
Israel leans on the English version, saying it is not obliged by the resolution to give up all of its 1967 gains.
A deliberate complexity
The precisely unspecific wording of the resolution is what enabled its unanimous adoption at the UN Security Council, phrasing that the British sponsors of the text and other backers - who side with Israel's interpretation - have defended in the many questions since.
In 1969, Britain's then foreign minister Michael Stewart told parliament that the failure to make clear that Israel was to withdraw from all the land it took in the Six-Day War was "deliberate".
This should be understood with the part of the text that calls for "secure and recognised boundaries free from threats or acts of force," Stewart said.
The 1967 lines are also not necessarily considered permanent.
Jordan, Egypt and Lebanon accepted Resolution 242 but have since opposed any talks while Israeli forces remain in the occupied territories.
The Palestinians initially rejected the resolution, saying it reduced their people to "refugees" within the occupied areas.
But in 1988, they agreed to negotiate with Israel on the basis of 242 and Resolution 338, which called for peace talks after a 1973 war, accepting for the first time a two-state solution of Palestinian and Israeli territories existing side by side.
Israel pulled out of the Sinai in 1982 and the Gaza Strip in 2005 but remains in the other occupied territories for 50 years.