Shortly after the Second World War, with the partition of Germany into four Allied zones, the four former allies – Britain, the US, France and the USSR – set up ‘military liaison missions’. These diplomatic organisations were designed to encourage dialogue and understanding between the powers now operating within Germany. In reality, they ended up providing the perfect opportunity to carry out intelligence-gathering missions in plain sight.
The British and Soviet missions, BRIXMIS and SOXMIS, were the first to be established with an agreement in September 1946. (Officially, BRIXMIS was the British Commanders’-in-Chief Mission to the Soviet Forces in Germany, but that’s a bit more of a mouthful.)