The last few years have seen a spike in dangerous nuclear rhetoric and outright threats to use nuclear weapons. During the Cold War period, it was widely understood that a conflict involving nuclear-armed states could escalate to the use of nuclear weapons. “Signalling” of nuclear intentions was usually understated and often occurred in the context of military-to-military contacts. In contrast, today’s reality involves much more explicit threats and aggressive rhetoric. Recent explicit and implicit threats of nuclear-weapon use by leaders of several nuclear-armed states have contributed to the creation of an unstable security environment. While certain threats and/or aggressive statements were made in the context of escalating tensions, others were issued almost entirely without preface and were ostensibly designed to achieve political objectives. This trend of using threatening rhetoric involving nuclear weapons against specific states for political purposes entails a broadening of their role beyond nuclear deterrence towards their use in nuclear “blackmail” or “compellence”.
For example, in 2015, the Russian ambassador to Denmark stated that “Danish warships will be targets for Russian nuclear missiles” should Denmark join NATO’s missile defence system. In March 2016, in reaction to the commencement of a US-South Korean military exercise, North Korea threatened to turn Washington and Seoul into “flames and ashes”. In August 2017, US President Donald Trump asserted that North Korea “best not make any more threats to the United States”, or “they will be met with fire and fury and frankly power, the likes of which this world has never seen before.”The next month, following the adoption by the UN Security Council of new sanctions against North Korea, the Korea Asia-Pacific “Peace Committee”, which oversees the country’s external relations, stated that the United States should be “beaten to death like a rabid dog” and Japan “sunken into the sea by the nuclear bomb of Juche”.
The trend has continued in 2018 and 2019:
- In his New-Year’s-Day speech of 1 January 2018, the North Korean leader Kim Jong-un stated: “The entire United States is within range of our nuclear weapons, and a nuclear button is always on my desk. This is reality, not a threat”.
- On 2 January 2018, in response to Kim Jong-un’s “button” comment, US President Donald Trump tweeted: “Will someone from his depleted and food starved regime please inform him that I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works!”
- On 1 March 2018, Russian President Vladimir Putin announced the development of an “invincible” new nuclear cruise missile. An accompanying video showed a computer animation of missiles raining down on Florida.
- On 12 March 2018, in the context of UK investigations into the attempted murder of a former Russian double-agent and his daughter in Salisbury, a spokesperson for the Russian Ministry of Foreign Affairs warned: “Who does Britain think it is, issuing ultimatums to a nuclear power?”
- On 22 July 2018, US President Trump tweeted (in capital letters) to Iran’s President Hassan Rouhani: “Never, ever threaten the United States again or you will suffer consequences the likes of which few throughout history have ever suffered before.”
- Visiting the Dimona facility on 29 August 2018, Israeli Prime Minister Benjamin Netanyahu warned Israel’s enemies that Israel has the means to destroy them. Netanyahu stated: “Those who threaten to wipe us out put themselves in a similar danger”. The Dimona reactor is believed to have produced the fissile material for Israel’s nuclear weapons.
- On 20 February 2019, in his annual State of the Nation speech, Russian President Vladimir Putin warned that, if the US stationed intermediate-range missiles on the European continent, “Russia would aim its weapons at those missiles and at targets in the United States.”
- On 26 February 2019, amid rising tensions between India and Pakistan, the latter publicly announced that it would convene a meeting of the National Command Authority (NCA), which oversees Pakistan’s nuclear arsenal. According to one observer, the disclosure of the NCA meeting was “clearly meant to be a threat of nuclear retaliation. ‘I hope you know what that [convening the meeting] means,’ the Pakistani spokesperson said. They also declared that Pakistan would ‘dominate the escalation ladder.’"
- On 27 March 2019, US President Donald Trump stated that Russia had to “get out” of Venezuela, and that “all options” were on the table if they did not.
- On 17 April 2019, Indian Prime Minister Narendra Modi stated: “In the past our people would weep, go around the world saying Pakistan did this, did that. It is now Pakistan’s turn to weep.” He further noted that India has “the mother of nuclear bombs”, and that he had told Pakistan: “do whatever you want to do but we will retaliate.”
- On 19 May 2019, US President Donald Trump declared on Twitter that he would bring about “the official end of Iran” should the latter want to fight. US nuclear-capable bombers had been deployed to a US base in Qatar, neighbouring Iran, the week before.
- On 23 July 2019, ahead of a meeting with Pakistan’s prime minister, US President Donald Trump asserted that “I have plans on Afghanistan that if I wanted to win that war, Afghanistan would be wiped off the face of the earth, it would be gone, it would be over in literally 10 days.” The comment was widely read as an allusion to plans to use nuclear weapons. At a news conference with Australia’s prime minister on 20 September 2019, Trump repeated this point, saying that “We’ve been very effective in Afghanistan, and if we wanted to do a certain method of war, we could win that very quickly, but many, many, really, tens of millions of people would be killed, and we think it’s unnecessary.”
While many of these outbursts arguably do not qualify as “threatening” to use nuclear weapons in a legal sense, they nevertheless challenge the norms of nuclear restraint and tradition of non-use. They also further increase incentives for nuclear proliferation and are incompatible with the NPT and the 2010 NPT Action Plan commitments to adopt policies compatible with achieving a world without nuclear weapons and to reduce the role of nuclear weapons in military and security policies.
 Reuters, “Russia threatens to aim nuclear missiles at Denmark ships if it joins NATO shield” (22 March 2015).
 AP, “North Korea threatens to reduce US and South Korea to ‘Flames and Ash’,” The Guardian (7 March 2016).
 P. Baker and C. Sang-Hun, “Trump Threatens ‘Fire and Fury’ Against North Korea if It Endangers U.S.”, New York Times (8 August 2017).
 J. McCurry, “We will sink Japan and turn US to ‘ashes and darkness’, says North Korea”, The Guardian (13 September 2017). “Juche” is North Korea’s state ideology of self-reliance.
 Newshub, “‘Nuclear button is always on my desk’” (1 January 2018).
 Donald J. Trump, Twitter (2 January 2018).
 BBC, “Russia’s Putin unveils ‘invincible’ nuclear weapons” (1 March 2018).
 P. Gourtsoyannis, “Russia warns UK”, The Scotsman (13 March 2018).
 Donald J. Trump, Twitter (22 July 2018).
 D. Williams, “At Dimona reactor, Netanyahu warns Israel’s foes they risk ruin”, Reuters (29 August 2018).
 N. MacFarquhar, “Threatening U.S., Putin Promises Russians Both Missiles and Butter”, New York Times (20 February 2019).
 J. Trevitchick, “Pakistan Promises Retaliation, Makes Nuclear Threats After Indian Jets Bomb Its Territory”, The Drive (26 February 2019).
 E. Zuesse, “Trump Threatens Nuclear War if Russia Protects Venezuela”, Modern Diplomacy (1 April 2019).
 C. McGrath, “Modi Warns Pakistan Against ‘Threats’”, Express (18 April 2019).
 Donald J. Trump, Twitter (19 May 2019).
 A. Ward, “Trump says he could wipe Afghanistan off face of the earth in 10 days”, Vox (22 July 2019).
 J. Wagner, “Trump says he could end Afghanistan war quickly but “tens of millions” of people would die, Washington Post (20 September 2019).