A staggering 300,000 troops are on display today in Russia - even more than were seen during the Cold War.
The Vostok 2018 war game involves more than double the number of regular troops in the entire British armed forces.
Vladimir Putin is expected to personally supervise the exercises in Siberia and the east of Russia where he will also host a key Eastern Economic Forum in Vladivostok.
Among the key guests in a bid to woo investors are the Chinese leader Xi Jinping.
NATO has condemned the war games as a rehearsal for "large-scale conflict” and they are seen as the largest in modern Russian history.