A nuke in LEO would make the environment so radioactive for some time to fry every single satellite that crosses the lower van allen belt. After some time (mont

A nuke in LEO would make the environment so radioactive for some time to fry every single satellite that crosses the lower van allen belt. After some time (months, may be a few years) radiation goes back to normal levels and you can launch satellites again. Fun fact, the first nuke in space had a lot of people very nervous as it was thought that making satellites impossible forever was a possibility, and quite a few did fail due to the nuke.