In terms of arms control, there was for example a nuclear non-proliferation treaty between the US and Russia up until the US withdrew in 2002.
You're thinking of the ABM Treaty, which George Bush withdrew from in 2002 (one of the many many stupid things he did that led us to this point). This was a treaty limiting missile defence systems. Bush said the US needed to withdraw because it needed to expand its missile defences against potential Iranian attack (total BS).
The US and Russia still have a nuclear arms control treaty, New START, in place. It was extended last year through to 2026. Who knows what will happen now though, it's very worrying.
I know a lot of people are worried about the nuclear angle, I might suggest having a look at the ICAN website -- the International Campaign to Abolish Nuclear Weapons:
www.icanw.org/
They won the Nobel Prize a few years ago and have done pretty well with the international treaty to ban all nuclear weapons.
The website has ways to get involved with the movement. Ordinary people have made such a huge difference in arms control efforts over the years, maybe some of you would find this interesting.