Donald Trump and Vladimir Putin fired the starting gun on a new nuclear arms race on Friday as they both vowed to launch a major expansion of their countries’ arsenals.
That appeared to be a response to sabre-rattling remarks hours earlier by Mr Putin.
Speaking at an end-of-year meeting with his defence chiefs, the Russian president said strengthening nuclear capability should be a chief objective for 2017.
We need to strengthen the military potential of strategic nuclear forces, especially with missile complexes that can reliably penetrate any existing and prospective missile defence systems, Mr Putin said.
He added: We must carefully monitor any changes in the balance of power and in the political-military situation in the world, especially along Russian borders, and quickly adapt plans for neutralising threats to our country.
He added: “We can say with certainty – we are stronger now than any potential aggressor. Anyone!”
Russia and the United States jointly account for over 90 per cent of the world’s nuclear weapons, fielding an estimated 7,300 and 7,100 respectively.
Both country’s arsenals are regulated by a series of bilateral arms limitation treaties that place strict limits on the numbers and kinds of warheads and delivery systems they can field. A rapid expansion of either country’s forces could shatter that arms control regime and plunge the world back into an era of Cold War style nuclear arms race.
Mr Trump’s statement marked a jarring departure from President Barack Obama’s position on the nuclear issue.
In a speech in Prague in 2009, Mr Obama called for the elimination of nuclear weapons.
His announcement came the day after Mr Trump met with eight generals and admirals in a military summit at his Mar-a-Lago estate in Florida.
Mr Trump made a series of aggressive statements about nuclear weapons during the election campaign, saying: I’m not going to take cards off the table. We have nuclear capability.
At one point he also said America would be better off if countries like Japan, South Korea and Saudi Arabia developed their own nuclear weapons.
Hillary Clinton repeatedly questioned Mr Trump’s temperament and his fitness to be in possession of the nuclear codes.
Ten former nuclear launch operators wrote a protest letter asserting he did not have the diplomatic skills to avoid a nuclear war.
According to his website Mr Trump recognises the uniquely catastrophic threats posed by nuclear weapons and his stated policy is to modernise the nuclear arsenal to ensure it continues to be an effective deterrent.
Following his latest statement there was an immediate surge in shares of companies producing uranium amid anticipation of more demand for it in the nuclear programme. Over the next three decades the Pentagon is expected spend $1 trillion upgrading its nuclear weapons systems.
Russia is currently in the midst of a multi-year nuclear upgrade programme, with new strategic missile submarines, upgraded strategic bombers, and new intercontinental ballistic missiles all under production.
In this sense Russia is one step ahead of the United States. Igor Sutyagin, an expert on the Russian military at the Royal United Services Insitute (RUSI).
However, Mr Sutyagin cautioned that Russia would be alarmed at the prospect of entering a Cold War-style bomb-building race, because the cost would be prohibitive and the United States would probably quickly outstrip Russian production.
That’s why these arms control treaties have lasted as long as they have Russia is more interested in maintaining them than the United States, he said.
Mr Putin will be very, very worried about statements like this coming from Washington, he added.
There was also confusion over whether Mr Trump’s statement was a call to increase the number of America’s nuclear warheads, or referred to modernising existing systems. There was no immediate clarification from the Trump team.
Daryl Kimball, executive director of the Arms Control Association, said: “Trump and his people need to explain the basis of his cryptic tweet. What does he mean by expand, and at what cost? He will be shocked by the skyrocketing costs of the current plan to modernise the US nuclear arsenal.”
Retired General James “Spider” Marks, a 30-year US Army veteran, said it was “concerning” that Mr Trump would discuss nuclear issues on social media.
He said: “That’s very concerning to me. It concerns me that our president-elect would do that.”
The exchange comes amid heightened tensions between Russia and Nato countries, which fear a repetition of Mr Putin’s recent military interventions in Ukraine and Syria. Sergei Shoigu, the Russian defence minister, said that NATO had doubled the intensity of its military exercises and that the majority of its drills were “anti-Russian”.
He also accused the British army of using Russian uniforms and equipment to designate the enemy in exercises on Salisbury Plain.
“[The British] have started to use Russian-made tanks and uniforms of the Russian military to designate the enemy,” Mr Shoigu said.
“The last time this training method was used was by Nazi Germany during the Second World War,” he added, according to a transcript published on the defence ministry’s website.
The UK’s ministry of defence denied the allegation.