Diverse sources of cruise-missile proliferation already exist. And, unlike the incremental way in which the ballistic-missile threat has unfolded, land-attack cruise missiles with stealth capabilities could emerge rapidly and at the same time as cruder, first-generation cruise missiles. Indeed, compared with the predictable features of planning against the Cold War's monolithic adversary, the emerging cruise-missile threat may well represent the prototype of twenty-first-century defence-planning challenges - multiple acquisition paths, uncertain development cycles and opaque monitoring environments. To avoid being caught unprepared for a future regional contingency, defence planners need to develop far better hedging strategies against this threat than they did against that of ballistic missiles in the 1980s. A critical near-term challenge is deciding upon an appropriate mix of defence investments and improved arms-control policies.