Kyrgyzstan, once part of the Soviet Union, is the only country that is home to both US and Russian airbases, an arrangement that hasn't always been tension-free. As riots erupted last week, hundreds of thousands of people fled the country and the government turned to Russia for military aid.

Russia supplied a small number of troops -- but only to protect its own base. Meanwhile, the US supports Kyrgyzstan -- but through financial assistance rather than arms.

Graphic by Jez Burrows.