So this is like Octopussy. What if a terrorist explodes a nuclear bomb near a central oil refinery in Saudi Arabia. The shock would reverberate thru the pipelines, starting fires and destroying a good piece of the world's energy infrastructure. Of course, the stock market will crash, the economy would be crippled for a lack of energy. Meanwhile, a simultaneous threat to do the same on a G8 nation (probably a city) is made. So, ppl would panic and attempt to flee the cities. The threat creates the vicious downward cycle as the same instrument of distribution needed to spread out is at a shortage; in effect disabling the G8 nations current state of existence.
This is a safer alternative to bombing a city for the terrorists and brings us back to the Octopussy theme. The oil fields are nuked, who is the US going to bomb; Saudi Arabia??? The terrorists win because forces would have to be mobilized for the state of emergency in the homelands. This may take months. And the world is not the same again.