Secret military files reveal when Russia would consider using nuclear weapons, including the destruction of 20% of its ballistic missile submarines: FT

• The Financial Times has obtained leaked files that show Russia's strategic planning for nuclear war.
• The documents outline scenarios in which Russia might deploy nuclear weapons, per the report.
• Details include how much of their military defense needs to be destroyed in order to go nuclear.

The Kremlin has considered a broad range of scenarios for when the country should go nuclear, leaked Russian military files obtained by The Financial Times showed.

The 29 leaked files pertain to tactical nuclear weapons and are dated from 2008 to 2014, meaning they're at least 10 years old. The weapons described in the files are meant for specific battlefield targets, and are not the intercontinental-range warheads aimed at wiping out entire cities.

But the documents do outline detailed conditions for how much of Russia's military defense system needs to be destroyed to trigger nuclear warfare, per the FT.

For example, Russia may use nuclear weapons if 20% of its strategic ballistic missile submarines are eliminated, the outlet reported. Such submarines are the ones capable of launching nuclear missiles that would trigger the all-out war feared during the Cold War.

Other thresholds of nuclear war include if three airfields or 30% of Russia's nuclear-powered attack submarines — such as the Yasen-class subs Moscow has continued to add to its naval fleet — are destroyed.

These files include details of wargames — war simulations often conducted for military strategic planning — and presentations for naval officers, according to The Financial Times.

Notably, they also include scenarios where China invades Russia, including conditions when Moscow might deploy tactical nukes in a first-strike decision.

Per the FT, one scenario involves using tactical nuclear weapons to stop China from pushing further into Russia with "second-echelon units," a term that typically refers to a second invasion wave that would support and reinforce an initial assault.

Such documents indicate that Russia has considered an attack from China even as Beijing and Moscow continued to build close diplomatic ties in the 21st Century.

In 2022, eight years after the most recent secret document was produced, both nations declared a "no limits" partnership. This pledge was to maintain close ties and bolster each other's economies and militaries.

Meanwhile, China has publicly maintained that it adheres to a "no first use" nuclear policy and would only use nuclear weapons in response to a nuclear attack.

The FT reported that a spokesperson for Russian President Vladimir Putin challenged the "authenticity" of the documents when asked about the nuclear files.

A spokesperson for China's foreign ministry told the outlet that Moscow and Beijing have "legally established the concept of eternal friendship and non-enmity."

The Chinese Foreign Ministry's press service did not immediately respond to a request for comment sent by Business Insider.

Since Russia invaded Ukraine in 2022, Putin has upped the ante around his nuclear rhetoric — so much so that some military officials and experts have begun to raise doubts about the Russian leader's threats.

In September 2022, after Russia began the partial mobilization of reservists for the war in Ukraine, Putin raised the specter of nuclear war, proclaiming that his warnings were "not a bluff."

The threats have concerned even one of Russia's closest allies, China's Xi Jinping.

Chinese and Western diplomatic officials previously told The Financial Times that Xi personally warned Putin against a nuclear war.