What happens if india and pakistan war for the fifth time using nuclear bombs

well its damn clear that since both the countries have got the nuclear weapons ...if the war starts between them then there will be no more Pak or India on the map of the earth...i think this is impossible between both the countries to have a war at this stage where the situation is quite controlled as compared to before!

pakistan dare not use atom bomb without the permission of USA.That is the reason it wages proxy war in kashmir and talks peace with Delhi