The Kremlin has revised its nuclear policy. Does that make the use of atomic weapons more likely?

The 4-year-old document has a bland, bureaucratic title — “Basic Principles of State Policy on Nuclear Deterrence” — but its contents are chilling, especially with its newest revisions.

Better known as Russia’s nuclear doctrine, the revamped version that was signed Tuesday by President Vladimir Putin spells out the circumstances that allow him to use Moscow’s atomic arsenal, the world’s largest.

This new version lowers the bar, giving him that option in response to even a conventional attack backed by a nuclear power. That possibly could include the use of U.S.-supplied ATACMS missiles by Ukraine to hit Russian territory — which Moscow says happened Tuesday when six missiles hit the Bryansk region.

Kremlin spokesman Dmitry Peskov emphasized that such strikes could potentially be a trigger for a nuclear response under the revised document.

Its first iteration was signed by Putin in 2020, and he approved latest version Tuesday, according to the Kremlin. It outlines when Russia could dip into its atomic arsenal.

Since Russia invaded Ukraine in 2022, Putin and other Kremlin voices have frequently threatened the West with its nuclear arsenal. But that hasn’t deterred Kyiv’s allies from giving it billions of dollars of advanced weapons, some of which have hit Russian soil.

The revamped document describes nuclear weapons as “a means of deterrence,” noting their use is an “extreme and compelled measure.” It declares that Russia “takes all necessary efforts to reduce the nuclear threat and prevent aggravation of interstate relations that could trigger military conflicts, including nuclear ones.”

Such nuclear deterrence is aimed at safeguarding the “sovereignty and territorial integrity of the state,” deterring a potential aggressor, or, “in case of a military conflict, preventing an escalation of hostilities and stopping them on conditions acceptable for the Russian Federation,” the document says.

“Nuclear deterrence is aimed to ensure that any potential adversary realizes the inevitability of retribution in case of an aggression against Russia and its allies,” it says.

While formulated broadly to avoid a firm commitment of nuclear use and keep the West guessing at Moscow’s response, the modernized version spells out conditions under which Putin could use a nuclear option in response to a conventional strike.

Changes in the doctrine have been in the works for months, and it’s no coincidence that Tuesday’s announcement of a new version follows by two days Washington’s decision to allow Ukraine to use such longer-range missiles to hit targets in Russia. For months, U.S. President Joe Biden has been weighing the risks of such an escalation.

The doctrine says Moscow could use nuclear weapons “in response to the use of nuclear and other types of weapons of mass destruction” against Russia or its allies, as well as “in the event of aggression” against Russia and Belarus with conventional weapons that threaten “their sovereignty and/or territorial integrity.”

Any aggression against Russia by a nonnuclear power with the “participation or support of a nuclear power” will be seen as their “joint attack” on Russia, the document says.

It adds that nuclear weapons could be used in these scenarios:

— If reliable information is received about the launch of ballistic missiles targeting the territory of Russia or its allies.

— If nuclear weapons or other weapons of mass destruction strike the territory of Russia or its allies, or are used to hit Russian military units or facilities abroad.

— If an enemy’s impact on critically important Russian government or military facilities could undermine retaliatory nuclear-strike capability.

— If aggression against Russia or Belarus involving conventional weapons that raises a critical threat to their sovereignty and territorial integrity.

— If reliable information is received about the takeoff or launch of strategic and tactical aircraft, cruise missiles, drones, hypersonic or other flying vehicles and their crossing the Russian border.

The president can inform military and political leaders of other countries or international organizations “about the readiness to use nuclear weapons,” or that he has already decided to use them.