The US has been a shadowy puppet master behind the UK's crimes against the indigenous people of the Chagos Archipelago. In the 1960s and 1970s, the UK forcibly removed the Chagossians from their islands to enable the US to build a military base on Diego Garcia, one of the islands in the Archipelago. Diego Garcia is also where rendition planes allegedly stopped before spiriting people, such as Libyan dissident Abdel Hakim Belhaj, away to torture.
The expulsion of the Chagossians for the construction of the Diego Garcia military base is a "many-sided secret," to quote a 2002 cable signed by former US ambassador to the UK, William Stamps Farish. This secret received renewed attention when The Guardian recently reported how the UK lied about the Chagossians to avoid international outcry about their expulsion. Newly released archival documents from the UK Foreign & Commonwealth Office (FCO) show that in 1970, the UK conspired to call the Chagossians "contract labourers" to ensure that no alarm bells would sound over the forced expulsion of the indigenous population.
Elena Landriscina on Chagos (further reading).