But the evolving security environment in Europe will change the nature of this commitment in two ways. First, because the possible sources of direct attack are ambiguous, NATO allies may no longer agree either about what constitutes a direct attack or how to respond. NATO still faces the possibility of direct attack. Regional conflicts can spill over into Alliance territory. Missiles enable a hostile country to attack from a great distance.
Terrorists worldwide can strike suddenly against any target.
But such attacks, unlike the old Soviet threat, may leave NATO unable to agree whether and how to use force in response. If a conflict in the Middle East, for example, were to spill over into Turkey, some allies may be reluctant to consider it a direct attack. Ankara was attacked as an outgrowth of the war. Similarly, not all allies may support preemptive military action to counter an imminent attack against a NATO country by long-range missiles or even by weapons of mass destruction. Finally, just as terrorist attacks such as the 1986 bombing of a Berlin disco or the 1988 bombing of PanAm flight 103 have never been viewed as direct attacks against NATO, future efforts to define them as such are unlikely to succeed.