1 Context

The development of nuclear weapons throughout the twentieth century profoundly altered the landscape of warfare and presented a severe threat to international security. Weapons of mass destruction (WMD) are a class of weapons that have the ability to cause large-scale destruction and loss of life, typically affecting a wide area and resulting in severe long-term consequences. They are generally categorised into three main types, nuclear, chemical, and biological weapons. The nuclear bombings of Hiroshima and Nagasaki by the United States in 1945, and the chemical attack in Halabja city in the Kurdistan region of Iraq by the Iraqi government in 1988 are examples of the most significant events in modern history, with the world having witnessed the devastating effects of WMDs and long-lasting consequences on people and societies [1, 2]. In particular, the atomic attacks on Hiroshima and Nagasaki not only demonstrated the catastrophic potential of WMDs, but also initiated a nuclear arms race, particularly between the United States and the Soviet Union, with enduring local and global repercussions.

Advancement and deployment of nuclear weapons in the twentieth century altered the nature of warfare and posed a significant threat to global security, with an estimated 23,360 nuclear weapons in 111 locations in 14 countries at the end of 2009, in which 96% of the total global nuclear weapons reside in Russia and the United States [3]. These developments in nuclear armament were witnessed against the backdrop of other ongoing global conflicts, including recent tensions in Eastern Europe and the Middle East, drawing in both Eastern and Western powers and underscoring the complex interplay of military strategy and international diplomacy [4].

As of early 2024, nine countries possess approximately 12,121 nuclear warheads, with the United States and Russia holding about 88% of the world's nuclear inventory. The breakdown is as follows: Russia (5580), United States (5044), China (500), France (290), United Kingdom (225), Pakistan (170), India (172), Israel (90), and North Korea (50) [5].

Amid the ongoing global upheaval following Russia’s invasion of Ukraine, Russia engaged in brinkmanship by threatening nuclear escalation. This tactic aligns with historical patterns observed during the Cold War, where the looming threat of mutually assured destruction from nuclear warfare deterred aggressive action. Contrary to suggestions of mutual de-escalation, it is primarily Russia that has continued to leverage nuclear threats as a means to deter NATO countries from intervening in support of Ukraine [6]. This behavior has heightened public fears about nuclear conflict, with discussions proliferating across social networks and other media platform [7]. The claim that both sides have 'likely backed down' due to the scale of these threats is misleading. Russia remains the principal issuer of nuclear threats in this conflict, aiming to prevent NATO involvement by signaling a readiness to escalate to nuclear options if necessary [6].

The use of weapons of mass destruction can have significant ecological, humanitarian, and health consequences. These consequences affect not only the individuals directly involved but also future generations. The devastating effects of the nuclear disaster in Hiroshima and the chemical attack in Halabja serve as clear examples of this irreversible damage [1, 2]. During and after such events, a humanitarian crisis ensues, including forced migration, resource scarcity, food and health issues, climate change, pollution, increasing crime rates, fear, and loss of loved ones and property [8]. The legacy of these weapons, from the atomic bombing of Hiroshima to ongoing conflicts around the world, serves as a constant reminder of the danger they pose.

The objectives of this study are to describe the immediate and long-term public health, psychological, humanitarian, and ecological effects of WMDs; analyse historical events like the nuclear bombings of Hiroshima and Nagasaki and the chemical attack in Halabja to understand their broad impacts; link these insights to current world conflicts and wars to highlight ongoing risks; emphasise the importance of international disarmament and non-proliferation efforts; and Recommend proactive measures for crisis prevention and preparedness and raise public awareness of the dangers of WMD consequences.

2 A lesson from history: two prominent examples of weapons of mass destruction use

2.1 Hiroshima and Nagasak nuclear attack

The atomic bombings of Hiroshima and Nagasaki occurred on August 6 and 9, 1945, respectively, during the final stages of World War II. The United States dropped two atomic bombs, one on each city, aiming to force Japan's surrender and end the war swiftly. The immediate explosions caused massive destruction and caused the deaths of an estimated 129,000 to 226,000 people [9]. Beyond immediate casualties, the survivors faced long-term health consequences due to radiation exposure, including increased incidences of cancer and other illnesses, highlighting the profound and lasting impact of nuclear warfare on human health and society [10,11,12].

2.2 Halabja chemical attack

The Kurdish people in Iraq faced serious human rights violations and large-scale atrocities. One of the most notable examples is the Anfal genocide campaign, which included the chemical attack on Halabja, a Kurdish city near the Iranian border [13]. This attack stands out as the most infamous and consequential massacre of campaign [14]. Chemical weapons were first used by the German army during World War I (1914–1918) [15]. The chemical attack on Halabja on 16 March 1988, which occurred during the Iran-Iraq war, is considered one of the most heinous acts against civilians in recent history. The use of mustard gas, sarin, and tabun resulted in the deaths of around 5,000 people, mostly civilians including women and children [16]. This attack intensely demonstrated the horrors of chemical weapons and their devastating impact on civilians. Survivors of the attack have suffered from severe health problems such as respiratory problems, blindness, and long-term neurological damage, with many still experiencing the effects of chemical agents even decades later [17]. This attack serves as a strong warning of the catastrophic consequences of WMD and reminds us of the urgent need for increased vigilance to prevent the use and spread of chemical weapons and others.

Nuclear and chemical weapons have both been used with devastating consequences, as detailed in Table 1, which illustrates their differences in scale and frequency. Nuclear weapons cause considerably more casualties and environmental impacts than chemical weapons. While the use of chemical weapons is absolutely horrific and has grave humanitarian consequences, the scale of destruction and long-term effects of nuclear weapons are far greater. According to Allison et al. [18], there have been numerous instances of chemical weapon use by different actors from 1900 to 2019, highlighting their persistent threat and the grave humanitarian consequences they entail. For instance, the Syrian Civil War saw the use of chemical weapons by the Syrian government in 2013, resulting in severe civilian casualties. In 2017, the Islamic State used chemical weapons against Iraqi and Kurdish soldiers.

Table 1 Describe the names of events, immediate impacts, and late impacts
Full size table

3 Hypothetical scenario: analysing global conflicts and WMD threats in geopolitical hotspots

The ongoing conflict between Russia and Ukraine, which began in 2014 with Russia's annexation of Crimea, has heightened global security concerns and garnered international condemnation [19]. The crisis expanded to eastern Ukraine, leading to pro-Russian separatist movements and a severe humanitarian crisis. This situation has strained diplomatic relations between Russia and several countries, particularly in Europe and the United States, and has elicited a response from the broader international community [20]. The involvement of The North Atlantic Treaty Organization (NATO), marked by its condemnation of Russia's actions and its political and military support for Ukraine, has further escalated tensions between Russia and Alliance [21]. The complexity is exacerbated by the potential use of Russia's extensive nuclear arsenal, raising concerns about the possible escalation and deployment of WMDs [22].

Focussing on other global hotspots, the nuclear threat posed by North Korea, the tension between China and Taiwan, the conflict between India and Pakistan, tensions involving Iran and its neighbours, particularly Pakistan and Afghanistan, ongoing civil wars in Syria and Yemen, and Iran's missile strikes on Iraq and Israel all contribute to a network of global security challenges. These regions involve states that either possess WMDs, are suspected of having WMDs, or have demonstrated an interest in acquiring WMDs. Escalation in conflicts involving such states carries the potential risk of WMD use. These issues collectively require attention and diplomatic efforts to mitigate their potential international consequences.

4 Discussion

Today, there is widespread fear and anxiety regarding potential conflicts around the world, particularly the possibility of nuclear attacks. The consequences of WMD are significant and can have far-reaching effects on various aspects of human life. However, it is important to note that the current level of fear contrasts with the anxiety experienced during the 1950s and 1960s. During this period, people witnessed the devastating impact of nuclear weapons in the cities of Hiroshima and Nagasaki [23] and lived in constant apprehension due to the imminent threat of a nuclear war between the United States and the Soviet Union during the Cold War. A notable example of this tension was the Cuban missile crisis of 1962, which brought the world dangerously close to a nuclear catastrophe [24]. In response to these threats, people took measures to protect themselves, such as building bomb shelters and participating in drill [23]. However, it is possible that the absence of any nuclear weapon deployment since 1945, the end of the Cold War, and the emergence of other global concerns such as climate change, pandemics, and cyberattacks may have led people to become complacent or desensitised to the nuclear threat. Some people may also harbor a false sense of security, believing that nuclear deterrence, diplomacy, or technological advances can effectively prevent or mitigate a nuclear conflict [25].

5 Physical health consequences of WMD

The use of weapons of mass destruction (WMD) can have devastating physical health consequences. Hiroshima and Nagasaki resulted in immediate and long-term effects, including acute radiation sickness, cancer, leukemia, and genetic mutations [10, 26]. At the end of 1945, hundreds of thousands of people had died due to exposure to intense heat, physical force, and ionising radiation emitted by the bombs in Hiroshima and Nagasaki [27]. In addition, current research has shown that survivors, known as hibakusha, continue to experience various forms of cancer, highlighting the ongoing health issues and the increased mortality they face decades later [28]. The Halabja chemical attack caused severe respiratory problems, neurological problems such as seizures, tremors, and confusion, eye damage leading to blindness, skin burns due to the effects of mustard gas, and birth defects [29]. Given the ongoing conflicts in the world, particularly between Russia and western countries, there is a real risk of the use of WMDs, such as tactical nuclear bombs, resulting in widespread destruction of infrastructure and cities, injuries, deaths, long-term health effects of radiation exposure, and ongoing humanitarian crisis [30].

5.1 Psychological consequences of WMD

The psychological consequences of the use of WMD can have severe and long-lasting effects, including trauma, anxiety, depression, and lack of access to mental health services [31]. The deployment of WMDs results in a variety of psychiatric disorders and increased vulnerability to psychological trauma among survivors [32]. For example, individuals who survived the atomic bombings in Hiroshima and Nagasaki reported symptoms consistent with posttraumatic stress reactions such as neurosis and somatization [33], as well as long-persisted psychological damage including depression and occasional mood changes similar to PTSD. These conditions are directly related to their experiences and the ongoing fear of the late health effects of bombing [28]. Studies have also noted a correlation between these atomic bombings and gross mental retardation [34]. Similarly, survivors of the Halabja chemical attack experienced severe psychological impacts, including PTSD, depression, and anxiety, highlighting the widespread mental health challenges following exposure to chemical weapons [35, 36]. Recent events, such as the war in Ukraine, underscore the psychological toll of nuclear threats and the profound anxiety and distress they evoke among global populations, thus stressing the urgent need for improved psychological support and mental health services in areas affected by or under threat from nuclear warfare [37].

5.2 Humanitarian crisis of WMD

War and the use of WMDs can precipitate a profound humanitarian crisis. Such crises are typified by severe negative consequences including mass migration, deterioration of public health, resource scarcity, food insecurity, increased crime rates, heightened fear, and loss of life and property. Historical examples include the bombings of Hiroshima and Nagasaki, which led to mass displacement and acute food shortages [38], and the chemical attack on Halabja, which caused population displacement, deaths, contamination of food supplies and agricultural resources, and increased prevalence [39, 40].

In the context of Ukraine, the conflict has mainly involved conventional warfare rather than the deployment of weapons of mass destruction. However, the persistent threat of nuclear weapons use by the Russian leadership, as noted in various statements, significantly escalates the conflict and discourages international intervention. This threat prolongs the humanitarian crisis, exacerbating displacement, infrastructure damage, and resource depletion [41], highlighting the impact of nuclear threats on the dynamics of the crisis in Ukraine. These instances underscore the catastrophic implications of war, particularly when augmented by the actual use or threat of WMD. Such conflicts inevitably lead to a humanitarian disaster characterised by a large number of displaced individuals, limited access to essential resources, numerous missing persons, extensive infrastructure damage, and significant increases in food insecurity.

5.3 Ecological impacts of WMD

Weapons of mass destruction can cause severe environmental damage and contribute to global climate change [42]. They produce radioactive fallout, leading to long-lasting environmental contamination and reduced agricultural production. Significant environmental harms include soil and water contamination, air pollution, and loss of biodiversity, as seen in the civilian nuclear energy disaster of Chernobyl (which was not a nuclear bomb) and the chemical attack on Halabja [43]. Moreover, even limited nuclear exchange could result in a nuclear winter, drastically reducing global temperatures and precipitation levels, severely impacting agricultural productivity worldwide, and massive ozone depletion would increase ultraviolet radiation reaching the Earth, compounding the environmental disturbances [44]. Should the ongoing global conflict persist or involve the use of WMDs, the impact on the environment and climate change would be devastating. Such actions would lead to lasting damage to ecosystems.

5.4 Treaty on the prohibition of nuclear weapons

The treaty on the prohibition of nuclear weapons (TPNW) emerged in 2017 as a response to the slow progress in nuclear disarmament, signaling a shift towards a humanitarian outlook that focuses on the dire consequences of nuclear weapons use. This paradigm shift was propelled by a coalition of non-nuclear states and civil society groups, who redirected the disarmament dialogue to emphasize catastrophic humanitarian impacts rather than purely military and security issues. represents a crucial pact that prohibits a range of activities related to nuclear weapons, such as their development, testing, production, accumulation, transfer, utilisation, and the threat of their use. In addition, it forbids any assistance, encouragement, or inducement in undertaking these activities [45]. Furthermore, the TPNW obliges member states to support victims of nuclear weapons use and testing and to undertake environmental remediation in areas affected by these activities. The TPNW entered into force in January 2021 and presently has 88 state parties. Although the TPNW marks a significant step forward in multilateral agreements, it is not unprecedented in banning the whole category of WMDs. Earlier treaties like the Chemical Weapons Convention and the Biological Weapons Convention have already banned entire categories of WMDs, with substantial success in eradicating these weapons. However, unlike these agreements, the TPNW has not yet led to the elimination of nuclear weapons, primarily because no nuclear-armed nations have joined the treaty. Despite this, the TPNW plays a vital role in highlighting the humanitarian and environmental risks of nuclear weapons and emphasises the need for global cooperation and diplomatic efforts to prevent their use [45]. The inception in 2017 came as a response to the gradual progress in nuclear disarmament, signaling a shift towards a humanitarian outlook that focusses on the dire consequences of nuclear weapons use. This paradigm shift was propelled by a coalition of non-nuclear states and civil society groups, who redirected the disarmament dialogue to focus on catastrophic humanitarian impacts rather than purely military and security issues [46].

5.5 Resistance of nuclear weapons states

None of the nine states possessing nuclear weapons (China, France, India, Israel, North Korea, Pakistan, Russia, the United Kingdom and the United States) have chosen to join or support the TPNW [47]. These states argue that the treaty is unrealistic, divisive, and incompatible with the current regime for nuclear non-proliferation and disarmament, particularly the treaty on the non-proliferation of nuclear weapons (NPT). They also maintain that nuclear deterrence is necessary and legitimate for their own security and that of their allies. Some of these states have criticised the TPNW for lacking a verification system and potentially undermining the prospects for dialogue and cooperation between nuclear and non-nuclear states [48].

6 Recommendation and conclusion

Historical and contemporary examples of nuclear weapons vividly illustrate their devastating impact on humanity, ecosystems, and global stability. Events such as the nuclear bombings of Hiroshima and Nagasaki and the chemical attack in Halabja underscore the urgent need for comprehensive international efforts towards disarmament and non-proliferation. The current geopolitical landscape, marked by ongoing conflicts and the persistent threat of nuclear escalation, demands enhanced crisis prevention measures and preparedness strategies. The Treaty on the Prohibition of Nuclear Weapons (TPNW) represents a crucial step toward addressing these challenges, emphasizing the humanitarian and environmental imperatives of nuclear disarmament. However, resistance from nuclear-armed states underscores the complex geopolitical dynamics and the necessity for sustained global dialogue and cooperation. Large-scale public awareness campaigns could play a pivotal role in shifting government positions towards the TPNW, influencing policy changes through heightened public pressure. Additionally, the increased nuclear risks in Ukraine should serve as a wake-up call to all states about the potential for nuclear annihilation, underscoring the urgent need for proactive initiatives. These initiatives must prioritize public education, psychological support for affected populations, and robust diplomatic efforts to mitigate the catastrophic consequences of WMDs and safeguard global security.