Originally Posted by
The Giant
[t]he Snarl is like a nuclear bomb. You can get a lot of leverage out of owning a nuclear bomb, because no one wants it dropped on them. But if everyone knows you only own one and then you use it on someone...then everyone left knows you don't have it anymore. Sucks for your one target, but it won't end well for you, either.
That's why the Dark One's actual plan is to use the threat of moving the Gate to extract concessions from the other gods and deter preemptive strikes against his followers. Those concessions will be significantly less than, "All of you be my slaves forever," because at that point, the calculus would change and some of the gods might risk the bomb getting dropped on one of them to end the Dark One's threat to their friends and family.