As discussed in Part I of this two-part article, nuclear weapons, contrary to their stated intent, do not yield an economic dividend. Defence expenditures go up, not down, once they enter the national security calculus. Nor do they yield a peace dividend. The risk of war goes up, not down.
The latest example comes from the joint US-Israel attack on Iran which began on 28 February 2026. When Iran, despite losing its top leadership and suffering from an incessant bombardment of a variety of targets, refused to submit to a ceasefire, the US said that it would bomb Iran back to the Stone Age. When Iran did not surrender, let alone unconditionally, the US upped the ante by saying that “a great civilization will die tonight.”
Most analysts took this to mean that the US was about to drop nuclear bombs on Iran, something it had not done since the August 1945 bombings of Hiroshima and Nagasaki in Japan. The implied threat to use nuclear weapons undermined decades of assurances by Washington to its allies that it was a reliable but mature and sober protector.
While a small arsenal might deter direct attacks, maintaining massive stockpiles is a strategy used by major powers primarily to dissuade neutral countries from entering the nuclear arms race
Today, a surprisingly large number of countries have the capability of manufacturing nuclear weapons and hitting targets that are thousands of miles away. These countries include Germany, Japan, Australia, South Korea, Italy, and Brazil. Many other countries can easily acquire boosted fission weapons and regional missile capabilities, including South Africa, Poland, Turkey, Algeria, Indonesia, and Argentina. A world of runaway nuclear proliferation is the single greatest threat to world peace and economic growth.
There are strategic reasons why even just threatening to use nuclear weapons is hazardous. Nuclear weapons are the most powerful weapons that have ever existed, but they do not automatically make a county safe. Leaders, including democratically elected ones, must be careful about what they say about nuclear weapons. In 1969, China and the USSR fought a border war in the far East, despite both possessing nuclear weapons. Israel was attacked in 1973 by Egypt and Syria, despite Tel Aviv possessing nuclear weapons. Argentina seized the Falkland Islands/Las Malvinas from the United Kingdom in 1982, despite the latter’s possession of nuclear weapons. There are a number of factors affecting the utility and the limits of nuclear weapons.
First, if nuclear weapons are widely perceived as immoral and repugnant, then no leader will use them. If another leader, even if they are not aggressive, knows nuclear weapons will not be sued, then conventional war comes to be seen as a safer alternative because it is assumed there will be no escalation to the use of nuclear weapons. Disputes and wars will likely be more common because the costs will be seen as much lower. This effect is called the stability-instability paradox.
However, second, if leaders believe nuclear weapons can be used, then it raises the costs of war, and makes it less likely that either nuclear weapons or conventional attacks will be launched. Having enough nuclear weapons to stop an opponent from attacking is called immediate deterrence. Immediate deterrence can be achieved with a small arsenal targeting the enemy’s cities and some tactical nuclear weapons for battlefield use.
Third, if leaders are afraid of an accidental nuclear launch, then they will want to minimize the number of nuclear weapons so that the probability of a mistaken attack is minimized. Also, if a leader believably promises to protect their allies, then their allies will forego building their own arsenals, reducing the total number of nuclear weapons. This will leave the nuclear weapon state with an arsenal much larger than most other states, most of whom will have no nuclear weapons, and because they are so small, will not even consider the costs of having to build nuclear warheads to catch-up with the principal nuclear weapon states. This is termed general deterrence, and requires an arsenal far larger than what is required for an immediate deterrent arsenal explained above. It is also the main reason why the larger powers insist on large arsenals, not to deter an attack, but to deter attempts at building new arsenals, even among neutral countries.
When leaders are not modest about their nuclear arsenals, they make non-nuclear countries feel insecure and increase their desire to develop their own. When US President Harry Truman demanded forcefully that the Soviet Union leave Iran in 1946, although he did not mention or intend a nuclear threat (as only the US had atomic bombs at that time), he caused virtual panic in Moscow, which led to an unrestrained nuclear build-up in the Soviet Union. When the Soviet Union acquired nuclear weapons, China, which had fallen out with the Soviets, proceeded to develop its own. When China developed nuclear weapons, it pushed India in that direction. Eventually, it was the 1971 war with Pakistan which compelled India to develop its own.
In 1971, when India was invading East Pakistan, US President Richard Nixon sent the nuclear-weapons armed aircraft carrier USS Enterprise into the Bay of Bengal to help Pakistan, unintentionally causing India to feel insecure and to detonate a nuclear device in 1974. In neither of these cases did the usually sober President intend on provocatively swaggering with nuclear weapons, but both had profound and irreversible effects on instigating nuclear proliferation.
If a leader is too vocal about their reliance on nuclear weapons to compel compliance, and they fail to provide assurances that nuclear weapons are instruments only of last resort, then they undermine general deterrence because smaller states are suddenly insecure and are incentivized to get their own nuclear weapons. Larger allies of the US, like NATO, will question the wisdom and credibility of a blustering nuclear-armed alliance leader. A widespread proliferation of nuclear weapons to many different states makes deterrence much more difficult because of the complexity of overlapping arsenals and possible accidents. For example, if the US felt compelled to launch its land-based Minuteman III ICBM missiles at China, they would have to fly over Russia’s Far East. This may be solved with a telephone call, but this solution may be far less successful with smaller states that do not possess long-range sensors or satellites.
Also, because nuclear weapons are much less expensive than large armies and navies, once they are widely deployed, they will significantly reduce the relative power of the larger nuclear armed states. Thus, a US President boasting about nuclear weapons and nuclear war, while in the short-term it seems like a useful tactic of coercive diplomacy, it is a long-term self-defeating mistake.
Both the US and Russia possess roughly 4,500 nuclear warheads each. The US defence budget is approximately $850 billion a year, greater than the sum of the next ten countries combined, of whom eight are US allies. Yet, the US administration is planning to raise it by 76% to $1,500 billion during fiscal year 2026.
Nuclear weapons do not reduce the probability that a conventional war would break out. Both the Americans and the Soviets had nuclear weapons when the Vietnam War broke out in the 1960s, and the Soviet-Afghan War in the 1980s and the Russian-Ukraine war in this decade.
The policies of the current US administration may have convinced Russia that nuclear disarmament is fraught with risk, and pushed China, Pakistan and India to accelerate the accumulation of their warhead stockpiles. They may also eventually push counties such as Turkey, South Korea, Brazil, Germany, Japan, and others to acquire their own independent nuclear arsenals.
Nuclearization is fraught with risk, since it propels a country’s rivals to either acquire nuclear weapons or to enhance their existing portfolio. It enhances the probability that a nuclear war would break out. It does not lower defence spending but diverts funding from social and economic programs that enhance the quality of life of its citizens.