Lebanon – Palestine: How Britain’s decisions shaped the border

For most readers in the United Kingdom, the line separating Lebanon from what was then Mandatory Palestine appears as a distant, static feature of ‘Middle Eastern’ geography. Yet this border—finalised in April 1924—was anything but inevitable. It emerged from eight turbulent years of diplomacy, rivalry, miscalculation, and competing national projects.
What might seem like a minor administrative undertaking between France and Britain was, in reality, a complex struggle involving imperial strategists, Zionist leaders, and early Lebanese nationalists.

Lebanon and Palestine—an accidental fault line: The legacy of Sykes–Picot

The story begins in May 1916 with the Anglo-French exchange of notes that produced the Sykes–Picot Agreement. The arrangement partitioned the eastern Mediterranean into three spheres:

an “international zone”
a British coastal corridor encompassing Haifa and Acre
and a French zone stretching further north.

The line separating the French and international areas happened—almost inadvertently—to slice through existing Jewish agricultural settlements. No one in London or Paris imagined that this detail would soon complicate every subsequent negotiation.

Britain’s rising leverage and the Balfour factor

What was still a theoretical map in 1916 became an urgent reality two years later. As the First World War progressed, Britain—not France—found itself bearing the military burden in the Levant. And with the Balfour Declaration of November 1917, Britain formalised a political alliance with an increasingly influential Zionist movement.

When Allied forces established the Occupied Enemy Territory Administrations in September 1918, Britain expanded its control northwards to include the Safed region. France accepted this reluctantly, but it triggered a deeper Franco-British contest over what, exactly, “Palestine” should include.

At that time, “Palestine” was not a political unit but an Ottoman geographic description referring to the districts of Jerusalem, Nablus, and Acre. Britain nonetheless intended to create a new entity under its mandate—one that required clear northern limits.

Where should Palestine end? Britain’s ambiguity vs. Zionist precision

For Britain, the exact location of the northern boundary was of limited strategic importance. For Zionist leaders, however, it was existential. A viable future state, they argued, needed access to the water resources of the Upper Galilee, particularly the Litani River and the springs near Mount Hermon.

In February 1919, the Zionist Organisation presented to the Paris Peace Conference a proposed border running south of Sidon, looping inland along the Litani, crossing into the Golan, and returning southward. Their justification was economic: water, not scripture.

France rejected the proposal immediately, insisting on the original Sykes–Picot line as its baseline demand. Two incompatible claims—French and Zionist—were now firmly established.

Lebanese nationalism enters the frame

France strengthened its position by backing the ‘nascent Lebanese nationalism’ that it had secretly been nurturing. In August 1919, it sponsored a Maronite delegation led by Patriarch Elias al-Howayek, who argued in Paris for a larger, autonomous Lebanon under French mandate.
France thus gained its own local partner—much as Britain had the Zionists—turning the border question into a three-way contest.

The Deauville Proposal: When theology became geography

Seeking compromise, Britain issued the Deauville Proposal in September 1919. For the first time, London adopted the formula that Palestine should stretch “from Dan to Beersheba”—a biblically inspired definition drawn from a historical atlas by Scottish theologian Adam Smith.

Ironically, while British statesmen invoked scripture, Zionist leaders avoided it: they believed their case was stronger when framed around irrigation, agriculture, and economic viability.

Yet this biblical reference would prove decisive. Because the British misidentified ancient “Dan” as the village of Banias, they unintentionally restricted their own negotiating flexibility. The Litani River lay far beyond this point, making its inclusion diplomatically—and scripturally—awkward.

French hard lines: The Litani must remain Lebanese

By February 1920, the French position was unambiguous: the Litani River, in its entirety, must remain within Lebanon.
For the Zionist movement, this was a serious blow. Chaim Weizmann personally pressed both French and British officials, warning that Palestine without the Litani, the upper Jordan, and the Yarmouk “would not be an economically independent state.”

But French resolve, combined with Britain’s biblical framing, left little room for manoeuvre.

Tel Hai and the shift in territorial calculations

A turning point came in March 1920 with the Tel Hai incident, which elevated Zionist security concerns in the Upper Galilee.
Responding to this, France proposed in June a border that pushed slightly north from the coast at Ras al-Naqoura, then curved inland to include Metulla and the Hula Valley as a finger projecting into Lebanese territory.

This compromise kept the Litani entirely within Lebanon while ensuring that Jewish settlements in the far north remained inside Palestine.

The final push: Zionist appeals fall on deaf ears

From summer to winter 1920, Zionist diplomacy intensified. Weizmann wrote impassioned letters to British leaders arguing that the Litani was “vital” for Palestine’s future and of marginal value to Lebanon. His pleas gained sympathy but no political traction.

British officials charged with negotiating the final agreement found themselves boxed in. As one diplomat candidly wrote, discussions had been constrained by “the historical basis”—a euphemism for the biblical map that Britain itself had introduced.

The 1920 agreement and Its aftermath

On 23 December 1920, Britain and France reached a preliminary agreement, adopting the French proposal for the Lebanon–Palestine boundary. A joint commission finalised the demarcation in February 1922. The British Cabinet approved it the following year.

The final treaty made only passing reference to water rights, focusing mostly on the Jordan and Yarmouk rivers. The Litani—whose inclusion Zionists had pursued relentlessly—was not mentioned at all.

One small section of the border between Metulla and Banias was left open for potential adjustment, but the broader framework was settled. Britain and France had drawn a line that still shapes Middle Eastern politics today.

A legacy still visible today

What emerged between 1916 and 1924 was not merely a boundary but a political geography that continues to influence conflict dynamics in the Levant.

The sections disputed today—such as the Shebaa Farms, the Golan edge, and the village of Ghajar—are direct outgrowths of compromises, cartographic misunderstandings, and imperial rivalries of that era.

For Britain, this history is a reminder of how decisions made in distant conference rooms echoed across a century. For Lebanon, the Zionist entity, and Palestine, it remains a lived reality—one that demonstrates how borders drawn with indifference or ambition can become permanent lines of tension.

Featured image via the Canary