I think you missed the best part..
SPIEGEL: Is fear, as at the thought of a nuclear weapon in the hands of terrorists, not something very natural?
Brzezinski: Certainly, such a notion is not entirely unrealistic, but on the other hand we are not confronted with the Soviet nuclear weapons arsenal. I do not wish to minimize the danger of a single or even multiple terrorist acts, but their scale is simply not comparable.
So in Brzezinsky's opinion, a single or even multiple terrorists acts with nuclear weapons is FUNDAMENTALLY different from what he faced during the Carter administration.
I think the impact on our country would be FUNDAMENTALLY identical!