Republican presidential candidate Donald Trump has reportedly taken an interest in the US nuclear arsenal. Just how big is that arsenal?

The US has nearly 2,000 nuclear weapons ready for launch, according to an independent count kept by the Federation of American scientists. While 180 are deployed in Europe, the bulk are kept on missile and bomber bases in the US. The smallest are four times more powerful than the “Fat Man” bomb dropped at Nagasaki; most are 10 times more explosive.

The weapons are the legacy of the Cold War years and their bitter, nuclear ideological struggle. In 1986, the global arsenal peaked at more than 70,000 warheads; today, after years of work by governments and arms control activists, there are just over 15,000. Many believe this is still far too many.

US president Barack Obama has made nuclear non-proliferation one of the signature issues of his administration, notably signing a deal with Iran to prevent that country from developing nuclear weapons, while tensions between Russia and the US have scotched optimism for further reduction in the two most powerful nuclear states’ on-call arsenals. Scientists tracking the possibility of doomsday said earlier this year that we are closer to it today than we were during most of the Cold War years.

Now imagine Trump and his favorite associate, Vladimir Putin, at that negotiating table.