Will Russia use nuclear weapons? Could Putin use nukes in Ukraine war following New Start treaty suspension?

As the Ukraine conflict continues, international onlookers remain concerned at the war’s ability to escalate into a nuclear situation at a moment’s notice.

The latest twist in the tale came as Vladimir Putin announced that Russia is suspending its membership in the New Start accord, the last surviving nuclear arms limitation agreement with the US.

In his state-of-the-nation speech just days from the one-year anniversary of his nation’s full scale invasion of Ukraine, he said that Russia ought to be prepared to restart nuclear weaponstesting if the US did, ending a global ban on such testing that has been in place since the end of the Cold War.

But would Putin ever actually order a nuclear strike? Here’s everything you need to know about Russia’s nuclear threat.

What does Russia’s suspension of New Start mean?

The New START treaty - signed in 2010 by then-US President Barack Obama and Russian counterpart Dmitry Medvedev - caps the number of strategic nuclear weapons both the United States and Russia are allowed to deploy - or make ready for battle.

It limits them to 1,550 deployed warheads, 700 deployed missiles, and 800 intercontinental ballistic missile launchers, submarine-based launchers, and heavy bombers equipped for nuclear armaments - deployed or non-deployed.

The treaty also means both sides are allowed to monitor the other’s deployed nuclear arsenals, with up to 18 inspections a year. These were paused during the Covid-19 pandemic, and talks between Moscow and Washington on resuming inspections were due to take place last November until Russia postponed them, Reuters reports.

Russia has declared it will continue to abide by the limits on nuclear weapons imposed by the New Start arms control treaty, despite the suspension of Moscow's participation in the accord. The Russian Foreign Ministry added that, in accordance with prior agreements with Washington, Moscow will continue to share information regarding ballistic missile test launches.

Is it something to be worried about?

Andrey Baklitskiy, a senior researcher in the weapons of mass destruction and other strategic weapons programme at the United Nations Institute for Disarmament Research, told The Guardian this was “a big deal”.

“Suspension of the treaty is not equal to withdrawal but in reality, it could become really close over time,” he said. Baklitskiy believed Russia would “probably” stick to the treaty limits for the time being, but it would be harder for the US to make sure they were complying. He suspected the US would suspend its participation as well.

“One silver lining is that the Russian decision is political and can be easily reversed if the overall political relations change…The problem, of course, is that there is no change of political relations in sight.”

Other commentators are not so rattled by the announcement, such as John Erath, senior policy director for the Center for Arms Control and Non-Proliferation, who described the action as "entirely symbolic” in an interview with the Washington Post.

According to Erath, Putin made the declaration only in order to put pressure on US President Joe Biden to speak with Russia about ending the conflict, “so Russia can dictate the terms under which that would happen”.

What nuclear weapons does Russia have?

Russia has the largest stockpile of nuclear weapons in the world. Though the exact number of nuclear warheads is a state secret, it is thought that Russia owns more than half of the world's 14,000 nuclear weapons.

Over 7,000 nuclear weapons is an alarmingly high figure, but the nation’s stockpile was once even greater; Russia's predecessor, the Soviet Union, had a peak stockpile of 45,000 nuclear warheads in 1986.

The tools at Russia’s disposal are also shrouded in secrecy, but intelligence estimates make for some pretty scary reading. The Tsar Bomba - developed by the Soviet Union in the early 60s - is the most powerful nuclear weapon ever created and tested, responsible for the largest man-made explosion in human history. It had an estimated explosive power of around 50 megatons.

In 2015, information emerged that Russia may be developing a new nuclear torpedo, up to 100 megatons - twice the power of the Tsar Bomba. The Status-6 Ocean Multipurpose System is thought to have been designed to create a 500 metre tall tsunami wave that can radioactively contaminate wide areas of an enemy’s coastline.

It is also designed to be immune to anti-missile defence systems. The weapon is unconfirmed, but during a 2018 state-of-the-nation address, President Putin claimed that Russia was now in possession of several new classes of nuclear weapon, including a nuclear powered underwater torpedo and a nuclear powered cruise missile with effectively unlimited ranges.

Could Russia use nuclear weapons on Ukraine?

In July 2014, following Russia’s annexation of Crimea, the Russian foreign minister stated that his country had the right to defend the peninsula using nuclear weapons.

Just under a year later, Putin said that during the invasion of Crimea he’d been prepared to put nuclear forces on alert, so it sounds like he would be prepared to use such weapons on the territory of Ukraine.

Speaking in the House of Lords in November 2021, former Navy chief Lord West of Spithead said: “The greatest risk to the survival of mankind isn’t global warming, it’s an accidental thermo-nuclear war.”

He added: “One has to look at the dreadful behaviour of Putin, not just around the Ukraine but in a number of other ways and his very loose talk about his de-escalatory policy of using a nuclear weapon should he be losing a conventional war, to see what the real risks are.”

Earlier this year, Chairman of the Foreign Affairs Committee Tom Tugendhat said Russia sees battlefield nuclear weapons as simply “a bigger bang” and could give a military order to use them.

The Conservative MP told the BBC’s Radio 4 Today programme: “The Russian military doctrine doesn’t work in the same way as the Nato military doctrine. They do assume that they may use battlefield nuclear weapons and they see them as just a, if you’ll excuse the expression, a bigger bang. They don’t treat fallout in the same way we do.”

He added that although the situation was “concerning,” it was not unprecedented for Russia to threaten nuclear action.

Recently, Dmitry Medvedev, a former president of Russia and close ally of Putin, said Moscow had the right to defend itself with nuclear weapons if it is pushed beyond its limits and that this is "certainly not a bluff".

Can Russian nukes reach the UK?

To put it bluntly: yes. As it stands, there are only five nations thought to have the technological capabilities to hit any target on the world map. These are the five nuclear weapons states of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT).

Under this treaty, only five countries are allowed to have nuclear weapons: China, France, the United Kingdom, the United States, and Russia. The five nuclear weapons states agree to not help any other nation build nuclear weapons. All other nations who sign the NPT promise not to build more nuclear weapons for themselves or others.

However, India, Pakistan and North Korea have also declared they have such armaments, and it is believed that Israel, Saudi Arabia, Iran, South Korea, and Taiwan also have nuclear capabilities. Recent tests suggest North Korean missiles could hit just about anywhere on Earth with the exception of South America. Israel is the only other state currently thought to potentially pose a credible nuclear risk to Europe.

Does Ukraine have nuclear weapons?

After the dissolution of the Soviet Union, Ukraine held about one third of the Soviet nuclear arsenal, the third largest in the world at the time. It also had significant means of nuclear design and production, but in 1994 agreed to destroy the weapons and join the NPT.

Technically, Ukraine does have nuclear weapons, but these are in Russian control. After the 2014 annexation of Crimea, the Russian Federation deployed nuclear-capable weapons to the peninsula; despite the annexation, Crimea is still internationally recognised as a Ukrainian territory.

There has been much debate in Ukraine as to whether giving up its nuclear arms in 1994 was the right thing to do. In 2014, Ukrainian MP Pavlo Rizanenko told USA Today that Ukraine may have to arm itself once again with its own nuclear weapons.

He said: "We gave up nuclear weapons because of this agreement [the NPT]. Now, there's a strong sentiment in Ukraine that we made a big mistake. In the future... we need a much stronger Ukraine. If you have nuclear weapons, people don't invade you."

Putin has cited concerns that Ukraine could develop nuclear weapons as one of his reasons for invasion, saying the “demilitarisation” of Ukraine is the “only objective controlling factor that we could observe and have a proper reaction to”.

He added: “Even the appearance of tactical nuclear weaponry in Ukraine, for us this means a strategic threat.”