Iraq–Syria border

Two mandates, one line

Until 1918 this land was all Ottoman. The border was one of many new lines drawn after the First World War, when Britain and France divided the Ottoman Empire's Arab lands.^[1] Their secret Sykes–Picot Agreement of 16 May 1916 split the region into spheres of influence, and gave Mosul to the French sphere.^[1]

The San Remo conference of 24 April 1920 turned those spheres into mandates. France took Syria and Lebanon, and Britain took Mesopotamia (Iraq) and Palestine.^[1] Mosul went to Britain after all. In return, Britain gave France a 25% share of Iraqi oil and agreed to pipe oil across the French sphere to the Mediterranean.^[1]

The Franco-British Convention of 23 December 1920 described the Iraq–Syria boundary only in general terms. It left the detail to a joint boundary commission, and a further agreement on 3 February 1922 changed it only slightly.^[1]

The League of Nations commission

The line used today comes from a commission set up by the League of Nations Council, which reported in Geneva on 10 September 1932.^[1] It split the border into five sectors. From the mouth of the Khabur, the line follows the thalweg of the Tigris (the deepest channel of the river) for about 5 km. It then runs in straight lines between hilltops and survey points to the Euphrates, and a final straight line of about 150 miles (240 km) takes it south-west to the Jordanian tripoint.^[1]

The hardest choice was in the Jabal Sinjar hills. A minority proposal, more favourable to French interests, would have run through a pass in the hills and split the Jabal Sinjar, where most Yazidis lived. The League accepted the majority's line, which kept the range whole.^[1]

At the Euphrates the line follows the river's thalweg upstream for a short stretch, then heads for a stone near the southern bank known as the Leachman boundary stone. In 1970 that stone was the only known permanent marker on the whole border.^[1]

“From the Leachman boundary-stone in a straight line to the point situated 30 kilometres from the minaret of Abu Kemal on the straight line joining that minaret to the point situated 3.2 kilometres north of Tell Romah; thence this latter line as far as its intersection with the frontier between Iraq and Transjordan.”^[1]

People on both sides

The US State Department's Geographer wrote in 1970 that the border was essentially artificial. There were no active disputes over its alignment, and herders still crossed it to graze and water animals as they always had.^[1] The same study noted that ethnic and kinship ties were much the same on both sides, which had long carried the risk of trouble spreading across the line.^[1]

2014 and after

In the summer of 2014 the Islamic State group seized large areas of both Iraq and Syria. It released a video called “The End of Sykes-Picot”, in which a fighter toured a border crossing that Iraqi soldiers had abandoned.^[3] Al Jazeera reported that the group blew up border posts between the two countries and declared an “end to the Sykes-Picot era”.^[4]

Iraqi forces retook the Al-Qaim crossing on the Euphrates in late 2017. It reopened on 30 September 2019, nearly five years after the Islamic State had seized it. Al Jazeera described it as the only crossing with Syrian government forces on one side and Iraqi federal authorities on the other; other crossings were controlled by Kurdish forces.^[2]