Russia has rehearsed the use of tactical nuclear weapons at an early stage of a conflict with a major world power. This is evidenced by secret military documents available to the Financial Times, UNIAN reports.
Experts who have reviewed these files have noted that Russia's threshold for the use of nuclear weapons is lower than it has ever publicly acknowledged.
"This is the first time we have seen such documents published in the public domain. They show that the operational threshold for the use of nuclear weapons is quite low, if the desired result cannot be achieved by conventional means," said Alexander Habuev, head of the Carnegie Eurasia Centre in Berlin.
It is noted that Russian military files leaked to the public include scenarios for Russia's preparations for a Chinese invasion. In total, the network leaked 29 classified documents drawn up between 2008 and 2014.
Although some of the files date back 10 years or more, experts say they are still relevant to Russia's current military doctrine.
One of the documents lays out rather broad criteria for a potential nuclear strike by the Russian Federation, including the enemy landing on Russian territory, the defeat of units responsible for the protection of border areas, or an imminent enemy attack using conventional weapons.
Other potential conditions include the destruction of 20 per cent of Russia's ballistic missile submarines, 30 per cent of its nuclear attack submarines, three or more cruisers, three airfields, or a simultaneous attack on the main and reserve coastal command centres.
The documents also state that the Russian military can use tactical nuclear weapons for a wide range of purposes, including "deterring states from using aggression... or escalating military conflicts", "stopping aggression", preventing Russian troops from losing battles or territories, and making the Russian navy "more effective".
According to Jack Wattling, a senior research fellow in ground warfare at the Royal United Services Institute, the materials are aimed at preparing Russian units for situations in which the country may need to use nuclear weapons, not at establishing a set of rules for their use.
According to experts, in the case of Ukraine, Russia is likely to have a higher threshold for the use of tactical nuclear weapons, as Kyiv does not have its own nuclear capability or the ability to launch a ground invasion of the same scale as the United States or China.
Russian authorities believe that a nuclear strike on Ukraine would likely lead to an escalation of the conflict and direct intervention by the United States or the United Kingdom, and "that's the last thing Putin wants," said William Alberk, a former NATO and US Department of Defence official.