This week, Japan hosts G7 leaders in Hiroshima, intending to highlight the risks of nuclear weapons and press for progress on disarmament.
However, with North Korea and Russia threatening nuclear war and China expanding its arsenal, there may be little enthusiasm for decisive action to achieve Prime Minister Fumio Kishida’s stated objective of a “world free of nuclear weapons.”
Here are some questions and answers about nuclear weapons and Japan’s aspirations:
Which G7 countries have nuclear weapons?
According to the Federation of American Scientists (FAS), the United States, Britain, and France all have nuclear arsenals, with Washington having an estimated 5,244 warheads.
The total, which includes stockpiled, reserve, and retired warheads, dwarfs France’s and Britain’s stocks, which FAS estimates at 290 and 225, respectively.
However, several G7 nations, notably Japan, either host US nuclear weapons or are covered by the US “nuclear umbrella” – an expectation that Washington would deploy the bombs in their defense if necessary.
What treaties deal with nuclear weapons?
The Nuclear Non-Proliferation Treaty (NPT), which opened for signing in 1968, is perhaps the most well-known nuclear-weapons treaty.
Parties include China, Russia, France, the United Kingdom, and the United States.
The treaty’s core is a vow by governments not to acquire nuclear weapons if they do not already have them, and for nuclear-armed countries to exchange peaceful technologies while working to reduce their arsenals.
However, nearly 100 UN member nations signed the Treaty on the Prohibition of Nuclear Weapons (TPNW) in July 2017.
Campaigners view the more recent pact as filling the NPT’s “gaps” by demanding the elimination of nuclear weapons.
No nuclear power has signed it and it is actively opposed by some.
France and the United States last year called it “at odds with the existing non-proliferation and disarmament architecture.”
The world has nine nuclear-armed states: the United States, the United Kingdom, France, Russia, China, India, Pakistan, North Korea, and Israel, which does not publicly admit its arsenal.
According to FAS, most nuclear-armed governments are seeking to expand their arsenals, with only Washington reducing its stockpile and France and Israel’s stockpiles considered stable.
The prospect of nuclear weapons use has resurfaced in recent months, with Pyongyang conducting new missile tests and Moscow issuing thinly veiled threats to use the bombs if it is attacked.