SWE

Explore World Nuclear Forces

During the Cold War there were about 70 000 nuclear weapons in the world. Since then the number has declined year by year. However, this trend has stalled. All nine nuclear armed states are modernizing, and some are increasing the size of their arsenals.

Explore the changes.

There are strategic weapons. They typically use long-range bomber and missile delivery systems on land and at sea and carry warheads with high explosive yields. They can reach strategic targets such as military bases, command and control centers and major cities on other continents.

There are also non-strategic weapons. During the Cold War they were also called tactical weapons or battlefield weapons. These usually have warheads with lower explosive yield have relatively short ranges. During the last year a new name has evolved: sub-strategic nuclear weapons.

There is no clear definition or argreement among the nuclear weapons-possesing states on the difference between strategic or non-strategic (tactical) nuclear weapons. This reflects the different roles they have in the military doctrines and plans.

First nuclear weapon

”Little Boy” was the first nuclear weapon used in war. It had a relatively low explosive yield compared with later nuclear warheads. The Hiroshima bomb was used by the U.S. to destroy a large city as part of a strategy to compel the Japanese government to surrender and end the war.

The yield of the explosion was later estimated at 15 kilotons (the equivalent of 15,000 tons of TNT).

Explore the numbers of warheads since 2005

Click or drag the chart to change year

Source: Sipri Yearbook 2026. The data are estimates, as of January 2026 and not exact numbers.

Hypersonic robots, drones and artificial intelligence

All nine nuclear-armed states are investing enormous sums in developing new and more modern nuclear weapons. This is happening at the same time as the old Cold War-era weapons are being phased out. Despite the overall reduction in total numbers, the number of warheads deployed with operational forces is increasing.

Around 2,100 to 2,200 are kept at the highest state of alert, deployed on ballistic missiles.

Below are three questions about nuclear weapons to Hans Kristensen, nuclear weapons expert at Stockholms International Peace Research Institute (Sipri) and the Federation of American Scientists (FAS).

Heightened alert

During the Cold War, nuclear weapons existed mainly to deter the opponent from using them. That is now changing.

In February 2026, the New START Treaty expired. For the first time in over 30 years, the US and Russia lack binding limits on the number of nuclear weapons and the ability to inspect each other’s arsenals. The world is once again reminiscent of the period after the Cuban Missile Crisis of 1962.

The risk that someone will use nuclear weapons first has increased. In 2019, the US and Russia withdrew from the INF Treaty, which had banned ground-launched intermediate-range missiles for over 30 years. Both countries are now developing such weapons.

Following the invasion of Ukraine in 2022, Russia raised the alert level of its nuclear forces. President Putin and other senior Russian officials have repeatedly spoken about the possible use of nuclear weapons.

“Russia’s population must get used to a scenario in which it is considered legitimate for Russia to use nuclear weapons,” the Swedish government wrote in May 2022 in an analysis that formed the basis for Sweden’s NATO membership in 2024.

Share of usable warheads rising in Russia

Since 2005, the United States and Russia have sharply reduced their total number of warheads. However, the number of operational (usable) warheads has not declined at the same rate. In Russia, the trend has reversed and the number is now increasing.

The charts below show how the arsenals of the two superpowers have developed since 2005. The height of the surface represents each country’s total number of warheads, while the red area shows the operational, usable warheads.

Click in the graphic to change year.

Usable warheads Other warheads

Although the overall number of nuclear weapons has fallen, the number of usable warheads in Russia is estimated to have increased since 2020. This is because old weapons have been dismantled and removed from the statistics, while new weapons have been deployed to operational units and military stockpiles.

At the same time, there is considerable uncertainty surrounding the exact figures because Russia lacks transparency, according to the peace research institute Sipri. The uncertainty is particularly great regarding non-strategic (tactical) weapons, where Russia is assessed to have a clear numerical superiority over the United States.

In some types of shelters, people can survive a nuclear attack. Sources: United states nuclear regulatory comission, Alex Wellestein (nuclearsecrecy.com), atomicarchive.com, Sipri Yearbook 2026, outrider.org

How Sweden nearly built the A-bomb – The hidden history

Sweden had advanced plans to acquire nuclear weapons during the Cold War. However, the project was abandoned in the 1970s in exchange for protection under the US nuclear umbrella.

The same information emerges from documents that SVT Nyheter (NEWS) has found in American archives. This is also stated by security policy expert Robert Dalsjö at the Swedish Defence Research Agency (FOI).

In 2019, Sweden’s defence minister said that no such American guarantees existed at the time.

What happens to “retired” nuclear weapons?

When a warhead is taken out of service, it is placed in storage pending dismantlement. This does not necessarily mean that it is taken apart immediately.

If nuclear weapons are dismantled, the highly enriched uranium from the warheads can be used in civilian nuclear reactors. Between 1993 and 2013, the United States and Russia had the “Megatons to Megawatts” agreement, under which the US bought uranium from Russia and used it in its nuclear power plants.

Plutonium can be blended down into so-called MOX fuel and used in nuclear reactors.

The United States and the United Kingdom have long-term storage for the plutonium remaining from dismantled warheads. Russia is assumed to do the same. Source: Sipri

Here you can check out more from SVT:s Data Journalist Team

Jonas Olsson

Martin Hedström

SVT Data Journalist Team

Source: Sipri World Nuclear Forces 2026

Updated: 8 june 2026