The United States, having established military bases in Central Asia after September 2001, has now become a force in what was previously predominantly a Russian sphere of influence; whilst China, Russia and Iran all continue to exert strong influence. These external, international influences have had a significant impact on local politics, with the overthrow of a long-standing regime in Kyrgyzstan, continued unrest and opposition to the current regime in Uzbekistan and the intensification of Chinese control in Xinjiang.