why do you think it is okay to shot down the moon instead of making nuclear-enable star inside out solar system?
This question is nonsensical, and I cannot answer it properly.  I assume you are trying to say it is okay to shoot down the moon instead of making a nuclear-enabled star inside our solar system.  While both of these things are bad, destroying the moon would likely cause less destruction than making a second star in the solar system.
What's wrong with making a second star in the solar system?
The solar system is a balance between gravity and movement - mainly the gravity from the sun and the centrifugal forces from the revolving of other celestial bodies. Adding another star, massive object, is going to severely disrupt the balance and the earth is likely to got shot into an unfavorbale orbit beyond the habitable zone had it not got destroyed by tidal force. Even if the orbit remained stable, the extra radiation from the second star would still lead to a global warming that could wipe out most of the life forms.
What would be the effect of destroying the moon with nukes?