Loading ...…is that it is not just the bomb alone that generates EMP. It is an interaction of the bomb with the ionosphere at a specific altitude that generates the EMP. It requires a high-altitude burst, and the effects are neccessarily widespread from that high altitude. The early tests in the pacific put out streetlights in Honolulu from over 1,000 miles away.
So I doubt that a nuclear burst EMP can be targeted to a ‘small’ area.
Still, with advance preparations, EMP damage can be minimized to some extent.