The First Gulf War was an armed conflict between a coalition of nations led by the United States and Russia against the Iran-Iraq Coalition. The war began in 1990 and ended in 1991, but estimated casualty levels were as high as 27,000. The cause of the war was the Confederation's invasion of the tiny neighbouring nation of Kuwait in 1990, created in the aftermath of the War of Jerusalem. After failing to comply to FWA demands, the alliance invaded the confederation. After several devastating losses, Iran-Iraq surrended a year later.