Data on the 9 nuclear-weapon states as of April 2019.
A dataframe containing :
The name of the country (character). The former USSR is listed here as Russia.
ISO 31661- alpha-2 two-letter country codes (character).
Date of first test of a nuclear weapon.
For Israel, which has not publicly acknowledged that it has nuclear weapons, this uses the Date of the Vela Incident.
number of nuclear weapons
number of weapons for which the yield in
(nYieldNA) = unknown or variable,
(nLowYield) = at most 15 kt
(kilotons), the size of the Hiroshima
(nMidYield) = greater than 15
but less that 50 kt, and
= at least 50 kt.
popM = estimated population in millions
popYr, per the Wikipedia
article for the indicated country on 2020-02-05.
GDP_B = nominal Gross Domestic Product
in billions of US dollars for year
GDPyr, per the Wikipedia article for
the indicated country on 2020-02-05.
Country code used by the Maddison Project.
Estimated date of the substantive commitment of the country to obtain nuclear weapons. See 'Details' below
Most of the contents of this dataset are
easily defined and not controversial. That's
not true for the date upon which each country
started its nuclear program, coded in
The following summarizes the rationale behind
the selection of the date for each country in
The Manhattan Project started in
stages. It was officially brought to the
attention of the US government by a
letter officially from
Albert Einstein to US President Roosevelt, 1939-08-02.
It was officially authorized
We use this later date as the date of the
start of the US nuclear-weapons program.
Russian scientists were studying uranium
before the first world war but didn't get
much official attention until the atomic
bombing of Hiroshima, 1945-08-06. Shortly
Stalin appointed Lavrentiy Beria. Beria
was a able administrator and guided the
project to fruition in four years.
British scientists were among the leaders
in nuclear technology in the late
nineteenth century. They welcomed
Otto Frisch and
Rudolf Peierls, who estimated
in 1939 that only
a few pounds or kilograms of uranium-235 might be enough to achieve a critical mass, whereas several tonnes of natural uranium would likely be required.
Because of the war, this information was
passed to scientists in the United States,
who developed it into the bomb dropped on
with help from British and Canadian
scientists and Canadian industry. After
the war, the US refused to share much of
the information developed in the Manhattan
Project with the British. British elites
felt disrespected by US. On
the British government decided to
initiate their own nuclear-weapons program.
France was one of the nuclear pioneers,
going back to the work of
Marie Curie and
Henri Becquerel in the
1890s. In 1956 the French were deeply
offended by the refusal of the US to
support them in the
On France and Israel secretly agreed to
collaborate in the development of nuclear
Mao Zedong reportedly decided to begin a Chinese nuclear-weapons program
First Taiwan Strait Crisis of 1954–1955.
That crisis was resolved shortly after
when China stated it was willing to
negotiate. We use this as the date of the
start of China's nuclear weapons program.
Indian scientists started research on
nuclear weapons before Indian independence
but didn't make a substantive commitment
to actually making a nuclear weapon until
they lost territory to China in the
that ended 1962-11-21. We use that date as
the date for the initiation of India's
Israel's first Prime Minister David
Ben-Gurion was reportedly "nearly obsessed"
with obtaining nuclear weapons to prevent
the Holocaust from recurring. For present
purposes, we use 1949-03-10, the date of
the end of the
1948 Arab–Israeli War,
as the beginning of Israel's
Pakistan's elite were totally humiliated
by their defeat in the
Indo-Pakistani War of 1971,
1971-12-03 / -16: That war ended the
Bangladesh Liberation War,
by which Pakistan lost over half their population and 14 percent of their land area.
Prime Minister Zulfiqar Ali Bhutto compared
Pakistan's surrender to the Treaty of
Versailles, which Germany was forced to sign
in 1919. Bhutto observed 1972-01-20 that a
Pakistani scientist had been part of the
Manhattan Project, and Pakistani scientists
could do the same in Pakistan. While
significant funding seemed not to have come
until later, 1972-01-20 is the date we will
use here for the beginning of Pakistan's
The 1950-1953 Korean War ended with a
cease-fire, not an official end to
hostilities. Since then North Korea has
perceived nuclear threats from the US. In
1956 the Soviet Union began giving North
Korean scientists and engineers "basic
knowledge" to help them initiate a
nuclear program. About 1962,
North Korea committed itself to what it called "all-fortressization",
which was the beginning of the
hyper-militarized North Korea of today.
North Korea reportedly asked the Soviet
Union for help with a nuclear weapons
program in 1963 and was turned down. China
turned down similar requests in 1964 and
1974. Around 1980 North Korea began mining
its own supplies of uranium and building
its own factory to produce
(See also Bolton, 2012.) For lack of
something better, we use 1980-01-01 as the
start of North Korea's nuclear weapons
program. They clearly wanted nuclear
weapons much earlier but didn't seem to
move seriously in the direction of
developing nuclear weapons until around
Overview from World Nuclear Weapon Stockpile
firstTest from Wikipedia, "List of states with nuclear weapons"
Derek Bolton (2012) North Korea's Nuclear Program (2012-08, American Security Program, accessed 2020-07-15) https://www.americansecurityproject.org/ASP%20Reports/Ref%200072%20-%20North%20Korea%E2%80%99s%20Nuclear%20Program%20.pdf
data(nuclearWeaponStates) plot(yearsSinceLastFirstTest~firstTest, nuclearWeaponStates, type='h', xlab='', ylab='') with(nuclearWeaponStates, text(firstTest, yearsSinceLastFirstTest, ctry))