In Disarmament Diplomacy No. 65, Sean Howard warned of the dangers of enhanced or even new types of weapons of mass destruction (WMD) emerging from the development of ‘nanotechnology’, an umbrella term for a range of potentially revolutionary engineering techniques at the atomic and molecular level.1 Howard called for urgent preliminary consideration to be given to the benefits and practicalities of negotiating an ‘Inner Space Treaty’ to guard against such developments. While echoing this call, this paper draws attention to the existing potential of nanotechnology to affect dangerous and destabilizing ‘refinements’ to existing nuclear weapon designs. Historically, nanotechnology is a child of the nuclear weapons labs, a creation of the WMD-industrial complex. The most far-reaching and fateful impacts of nanotechnology, therefore, may lie – and can already be seen – in the same area.