In deploying NMD, the challenge facing the US is to devise a package of incentives that will secure Russian agreement to amend the ABM Treaty. The most promising would involve US concessions in a future START III Treaty to accommodate Moscow's interests. In particular, the US could allow Russia to deploy multiple independently targetable re-entry vehicles (MIRVs) on mobile intercontinental ballistic missiles (ICBMs), which are far less destabilising to the nuclear balance than many arms-control advocates assume. In addition, before making a deployment decision, the US should give greater attention to several 'boost-phase' NMD concepts which could produce a more effective defence with fewer negative consequences for relations between the major powers.