Military commanders from both China and Russia discuss the joint exercises for the Vostok-2018 (East-2018) military drills at the Tsugol training range in the Trans-Baikal region in Russia on September 11, 2018. Photo: Fan Yongqiang/Xinhua

The Russia Military Air Fleet conducts an air-drop training during the Vostok-2018 (East-2018) military drills at the Tsugol training range in the Trans-Baikal region in Russia on September 11, 2018. Photo: Yang Zaixin/Xinhua

Soldiers from both Russia and China take part in a helicopter air-landing drill during the Vostok-2018 (East-2018) military drills at the Tsugol training range in the Trans-Baikal region in Russia on September 11, 2018. Photo: Yang Zaixin/Xinhua

Chinese tanks conduct a high speed impact drill during the Vostok-2018 (East-2018) military drills at the Tsugol training range in the Trans-Baikal region in Russia on September 11, 2018. Photo: Yang Zaixin/Xinhua

Chinese soldiers conduct a quick landing drill during the Vostok-2018 (East-2018) military drills at the Tsugol training range in the Trans-Baikal region in Russia on September 10, 2018. Photo: Yang Zaixin/Xinhua

The soldiers from both Russia and China take part in an exercise coordinating land and air so as to cross water barriers during the Vostok-2018 (East-2018) military drills on September 11, 2018. Photo: Yang Zaixin/Xinhua

A Russian soldier stands guard in front of a radar installation during the Vostok-2018 (East-2018) military drills at Telemba training ground, some 130 km north of the Siberian city of Chita, on September 12, 2018. Photo: Mladen Antonov/VCG

A helicopter flies over a convoy driving along the coast of the Chukotka Autonomous Area during the Vostok-2018 (East-2018) military drills on September 12, 2018. Photo: TASS/VCG

Workers prepare the S-400 missile system for the Vostok-2018 (East-2018) military drills at Telemba training ground on September 12, 2018. Photo: TASS/VCG