In general, the Iranian claim to Sistan rested upon two major grounds: ancient rights and present possession. The Afghan claim, on the other hand, rested primarily on its recent exercise of sovereignty over Sistan, i. e., from 1747, when the province formed a part of the Afghan Empire, until 1855, when Iran began to exercise considerable, if not complete, control over it.
In the arbitral award Sir Frederic first disposed of the Iranian claims based on ancient rights. He found them to be uncertain and not clearly supported by historical evidence. Conversely, he found more than a century of Afghan control over Sistan to be cogent evidence in favor of Afghanistan. The second question, i. e., “present possession,” was more difficult. Although it was clear that since 1855 Iran had exercised considerable authority over Sistan, it was problematic what the term “Sistan” included at the time of arbitration. It was “very vague/’ the award said, “for ancient limits have long become obsolete.”
The arbitration award distinguished between “Sistan Proper” and “Outer Sistan.” The former was “compact and concentrated” and the latter was “detached and irregular.” These two Sistans were separated by the Helmand River. The award gave Sistan Proper to Iran, on the grounds of geographical and political requirements, and Outer Sistan to Afghanistan, which was also given both banks of the Helmand above the Kobah Band. Furthermore, the award emphatically stated that “no works are to be carried out on either side calculated to interfere with the requisite supply of water for irrigation on the banks of the Helmand.”
In spite of the award the problem continued. “The lasting disadvantages of a boundary which cuts an irrigation system into two” were prophetically foreseen by an astute student of British policy at the time. In commenting on the award, Rawlinson stated, Indeed it would seem that tied as he [Goldsmid] was by definitive conditions of procedure, no other course was open to him than that which he adopted ; but at the same time it is impossible to avoid seeing that there is not one element of permanence in the recorded terms of settlement. . . It must occur to every student of political geography that the refilling of the old or western bed of the Helmand, which the river left only forty years ago, and to which it may at any moment return, would alter the whole hydrography of the province, and annihilate those distinctive physical features on which the recent arbitration was based.
This was almost exactly what happened in 1891. The Helmand began to change its course. By 1896 the main channel of the river flowed considerably west of the channel which Goldsmid had designated as the boundary in 1872. The local governors of Iran and Afghanistan managed to compose their differences over utilization of the water for a number of years, but in 1902 Iran felt that the problem should again be referred to the British for arbitration because the local officials were no longer able to handle the matter. In requesting the appointment of a new arbitrator, however, Iran made it absolutely dear that any award that might be given “must completely comply” with Goldsmid’s award of 1872.
Great Britain complied with the request and dispatched Henry McMahon to head an arbitration commission to Sistan. Having completed its exhaustive studies, the commission gave an award in 1905. Its fundamental point was that Sistan had often suffered, not so much because of a shortage of water but because of flood. On the basis of this observation, the award provided that Iran should have one-third of the water of the Helmand River from the Kamal Khan Dam down. It also repeated the earlier injunction that no works were to be carried out by either Iran or Afghanistan that would interfere with the requisite amount of water needed for irrigation on both sides of the banks of the Helmand. Subject to this important provision, however, both countries were allowed to cut new canals or reactivate old ones on either side of the river.
Iran vigorously protested the award, objecting in particular to its small share of the water. Iran believed that the award was incompatible with Goldsmid’s ruling in 1872 and that it could therefore be rejected. The Foreign Office retorted that Iran could not reject it; the Iranian government might only appeal to the British government if it had any reasonable grounds for complaint. It also warned that should Iran fail to file an appeal within a reasonable period of time, the award would be regarded as final and binding. The Helmand River problem had not been settled.