As usual, most commentary on North Korea's rocket launch last week focuses on the politics and diplomacy of Pyongyang's delinquency. But it is worth exploring the strategic implications more specifically. These are significant, but not straightforward. The apparently successful launch of a three-stage rocket makes it rather clearer than before that North Korea has both the capacity and the intention to build an intercontinental-range ballistic missile (ICBM). It is now prudent to expect that in perhaps as little as a decade, if North Korea survives in its present form, it may well have an operational ICBM capability. This would give Pyongyang the capacity to deliver a small number of probably relatively low-yield nuclear warheads onto American cities.