The agreement between Britain and Mauritius over control of the Chagos Islands has become one of the most controversial topics of this Parliament. This is a sorry reflection on the state of UK politics. In more normal times, the Chagos deal would be viewed as a diplomatic success story – an example of two states working together to uphold the rules-based international order for the benefit of all concerned.

But these are not normal times. Ever since the government of Liz Truss announced in November 2022 (with the backing of the Biden administration) that it was opening negotiations with Mauritius, critics have scoffed at the idea of “surrendering” the islands to a foreign power. In recent weeks, the accusations of treachery have reached a fever pitch – stoked in no small part by Donald Trump and his friends on the hard right of UK politics.

The Liberal Democrats have a critical role to play in ensuring that the Chagos agreement goes through. The legislation needed to implement the treaty, the Diego Garcia Military Base and British Indian Ocean Territory Bill, is currently in its final stage of the legislative process. Having cleared its third reading in both the House of Commons and the House of Lords, all that remains is for MPs and peers to iron out the final text of the legislation so that it can receive royal assent.

In the Lords, however, the Labour Party cannot do things alone. It depends upon the cooperation of others. The purpose of this blog post is to ask the Liberal Democrats to offer such cooperation at this all-important juncture.

I have studied the Chagos Islands for 18 years. From my perspective, the rights of the indigenous Chagossians have always been the most important dimension of the Chagos dispute. Having lobbied many of your elected representatives and peers over the past two decades, I know that the Liberal Democrats feel the same way. Why, then, do I support the Anglo-Mauritian agreement when so many Chagossians seem to oppose it?

The key thing to remember is that the Chagossian community is divided on the issue of sovereignty. This should not be surprising given that the Chagossians and their descendants number in the thousands and are spread across several countries. They have conflicting interests, identities, and ideas about their homeland – just like any other large group of people.

The largest Chagossian group – the Chagos Refugees Group, based in Mauritius – supports the agreement as a step in the right direction. This is for the simple reason that Mauritius has offered to facilitate a resettlement of the Chagos Islands whereas Britain has blocked the islanders’ right of return for the past 50 years. Many Chagossians in Britain also support the agreement for the same reason. I think it’s important that we listen to these Chagossians.

Of course, there are several UK-based groups that oppose the deal. They wanted to be involved as participants in negotiations over the islands. Some demanded a veto over the outcome. Rightly or wrongly, London and Port Louis were unwilling to grant these demands.

There is no sugarcoating the disappointment of the anti-treaty islanders. But we must ask whether torpedoing the present agreement will help their cause. My view is clear: it will not.

We need to be straight with the islanders: Britain will never grant their right of return. As Liberal Democrats, you know this all too well. You tried to do right by the islanders when you were in government. Vince Cable and others were strong supporters of the Chagossians, pushing for a feasibility study into resettlement. It wasn’t enough; the right of return went unrestored despite your best efforts.

The truth is that British governments of all persuasions – Labour, Tory, and Liberal Democrat – have failed to support resettlement even when the Cabinet has included sympathetic figures. There is no evidence that this will change if the Chagos agreement falls through. Rather, an historic opportunity will have been missed for no good reason.

For anyone who cares about the Chagossians’ right of return, this ought to be the smoking-gun argument that persuades them to back the deal: the Anglo-Mauritian treaty will facilitate a Chagossian right of return whereas the status quo ante did not and will not. For the first time in more than half a century, a pathway exists to secure the Chagossians’ most fundamental human right. If there is anything about the deal that should excite parliamentarians, it is this. Failure to follow through now would be cruel and catastrophic.

One common refrain is that Chagossians want to remain British. But this has nothing to do with the Chagos agreement or the bill currently before Parliament. Anyone born in Chagos before 1973 is already a UK citizen. Their direct descendants also have the right to apply for citizenship via the Nationality and Borders Act 2022. In short, any Chagossian who wants to be British can remain British, and so can their descendants. It is distressing that this fact has been distorted in media coverage.

It is a similar story when it comes to the issue of compensation. Some Chagossians want the UK to pay more in financial restitution. This is a reasonable ask – but again, it has nothing to do with the issue of sovereignty.

When the broad contours of the Chagos agreement were announced, I called it a “win-win-win-win” in the sense that it serves all parties’ core interests and jeopardizes none. The treaty’s provisions mean that Britain can conform with international law, keep supporting the US base on Diego Garcia, and play an honorable role in facilitating the Chagossians’ resettlement of their homeland. For its part, the United States gets to not only keep its military base, but put that base on sound legal footing for the first time in its history. Mauritius achieves its long overdue full decolonization. And the indigenous Chagossians secure their right of return, albeit to the Outer Chagos Islands and not Diego Garcia at this time.

If the treaty is not ratified, however, then none of these benefits will be realized. This would be a tragedy – one that the Liberal Democrats can help to avoid.

* Dr. Peter Harris is an Associate Professor of Political Science at Colorado State University, a Non-Resident Fellow with Defense Priorities, and a Research Fellow with the Modern War Institute at West Point. He is a dual UK-US citizen and previously volunteered with the UK Chagos Support Association. He is not a member of the Liberal Democrats.