Now.... let's just stop and review this for a second.... maybe the OP is onto a gem of an idea. We could get rid of Pakistan and India. Win.... Win. Hmmmmm.
HAHA
Why stop there? We can lay out a radioactive line of death just south of the Rio Grande. The Candians that speak French? Piss on'em! BOMBS AWAY!! Somila is on the way to India and North Korea is just south of China.
I'm sure we can avoid mass extinction if we know which way the wind blows.
And Hindus believe in reincarnation, so it's not like we can permantly kill them.
I can see it now

Mushroom clouds as far as the eye can see. I'm getting all weepy just thinking about it.
In principle I agree with you about nuking not only our enemies but also our economic competitors, like India and China.
But we have to be very careful about ensuring that the winds don't blow it back our way.
These are the parts of the world that we should nuke for being evil:
1) Germany and France
2) Gaza Strip
3) Syria
4) East Jerusalem
5) Iran
6) Pakistan
Also, we should nuke these two for taking our jobs
6) China
7) India
And finally.
8) Wales, Scotland and Northern Ireland
(since they give England a bad name)
If we have any nukes left, we may as well nuke our cold war enemy Russia... we should have done it years ago.