How many countries have nuclear weapons and how many are there? How destructive are today’s nuclear weapons? What about “nuclear deterrence” theory? Do nuclear weapons help keep the peace? What is the Treaty on the Prohibition of Nuclear Weapons? What is nuclear sharing and who is involved? Can a NATO state join the TPNW? What about the Middle East? Why does this treaty matter if none of the countries with nuclear weapons have joined? Did Ukraine give up nuclear weapons? Why should one country give up its nuclear weapons if other countries still have them? Why should countries that don’t have nuclear weapons care about this treaty? What is the “Eurobomb” and why are European politicians talking about it? What are "tactical" nuclear weapons? What are 'dirty bombs'? What are space nuclear weapons? Who makes the decisions around the nuclear weapons stationed abroad? What are the risks of nuclear sharing? Is nuclear sharing legal? Will the US and UK resume nuclear sharing at Lakenheath air base? What is the nuclear test ban treaty and why has Russia revoked its ratification? What is the New START Agreement and why has Russia suspended its implementation? What are gravity bombs and why is the US building the new B61-13 nuclear weapon? What about attacks on nuclear facilities?

What are gravity bombs and why is the US building the new B61-13 nuclear weapon?

Answer

Gravity bombs are bombs that are dropped from a nuclear-capable aircraft. They are currently being re-designed with new guidance systems, even so, they are still massively destructive  bombs that can not be used without indiscriminately killing civilians and destroying critical infrastructure – which is against international humanitarian law and would almost certainly be a war crime.  A single B61-13 bomb would be up to 24 times as powerful as the one dropped on Hiroshima. 

In October 2023, the US Department of Defense announced the development of a new nuclear bomb, pending Congressional authorisation and appropriation.  The B61-13 would be a new gravity bomb, of a much higher potential yield than the B61-12, which is currently replacing other versions deployed in Europe. It is expected that 50 bombs are likely to be produced in 2025, according to the Federation of Atomic Scientists. 

The decision to build the B61-13 increases proliferation risks. It is even controversial within certain forces in the US, according to the Federation of Atomic Scientists, as it is seen as a political, rather than military decision that “would cost a lot of money that could be better used elsewhere.” 

The cost of developing these modified missiles would come on top of the already vast sums the US spends on its nuclear arsenal each year, public money that could be spent on health care, education, disaster relief and other vital services that benefit the public.