Limited Use of Diego Garcia Reflects its Diminished Value After Handover
Both before and after the devastating US attack on Iranian nuclear enrichment sites at Fordow, Natanz and Isfahan, US deployments of aircraft to the Naval Support Base airfield on Diego Garcia are illustrating the flaws in the agreement which the United Kingdom and Mauritius agreed on May 22, following the US administration’s support for the deal.
The agreement hands formal sovereignty of the archipelago, which has been owned by the United Kingdom since 1814, to Mauritius, in return for an immediate leaseback of the Diego Garcia base and a surrounding 24-mile buffer zone to the UK. The deal in theory permits the continued operation of the joint UK/US base on the island for the next 99 years, an additional 40-year extension, and with a right of first refusal thereafter. The deal is not yet legally ratified, but common practice is to respect provisions of such international agreements during ratification periods.
Amongst a number of clauses to the agreement is one which obliges the United Kingdom to ‘expeditiously inform’ Mauritius of any attack mounted on a third party directly from Diego Garcia. The clause could be subject to a wide variety of interpretations, and the UK’s Attorney General is already indicating that he believes this to encompass an obligation to report such attacks in advance. Mauritius is a close ally of China, so the obligation to inform could result in breaches to operational security of US and British plans. In due course, there is to be an official Mauritian presence on Diego Garcia, able to report on comings and goings – and provide even earlier warnings and indicators to friends in Beijing.
At a time when the United States is deploying hundreds of additional aircraft into airfields in and adjacent to the region, nothing much seemed to change on Diego Garcia - indicating that in any contingency planning for operations against Iran, Diego Garcia did not feature as a forward operating base. On June 19, in the run-up to the US attack on June 21/22, the complement of aircraft seen in a snapshot of the South Ramp at Diego Garcia included four B-52s, six F-16Es, five KC-135s and one large transport aircraft - the same force composition which has been in place since US B-2s left the airfield on May 25.
In the hours after the attack, this force composition had changed very little. In imagery taken around midday on June 22, there were still the same four B-52s, six F-16Es, five KC-135s and one large transport aircraft on the South Ramp, suggesting that none of the aircraft were directly involved in mounting the attacks on Iran.
US operational planners have some flexibility in making contingency plans. They appear to have chosen to avoid any potential problems by minimizing the use of Diego Garcia in their campaign strategy. But in the long term, the conflict over Iran is a test of the UK-Mauritius agreement.
There will no doubt be a review post-campaign of the continued utility of the base if its operational use is stymied in times of tension. If it was decided that mounting elements of the attack from Diego Garcia would either have caused legal difficulties for the United Kingdom, or compromised operational security by virtue of the need to notify Mauritius, then the whole purpose of the agreement - for the United States to have continued use of a secure base untrammeled by the need to secure diplomatic permissions - may have been undermined. The United Kingdom will not only be committing to paying Mauritius an annual rent of $220 million for each of the first three years, $160 million for the next ten years, and then $160 million adjusted annually for inflation thereafter, all a cost to the UK defense budget - but the value of the base to the United States will have been diminished.