The Anglo-Soviet invasion was instigated in response to Reza for having denied the request to remove the German residents, who could threaten the Abadan refinery. Reza Shah further refused the Allies' requests to expel German nationals residing in Iran, and denied the use of the railway to the Allies. However, according to the British embassy reports from Tehran in 1940, the total number of German citizens in Iran – from technicians to spies – was no more than one thousand. Because of its strategic importance to the Allies, Iran was subsequently called "The Bridge of Victory" by Winston Churchill.