the co2 and h2o isn't frozen, its GONE.
Jesus man, don't you ever watch the History Channel?
okay, here is what happened. One day, Mars was enjoying a nice little day on its red planet with its own life. Suddenly, BLAM! This giant Solar Wave comes and wipes out the atmosphere of mars. Mars is now Vulnerable to anything. The Sun. Without the atmosphere, the sun is hotter than it is with an atmosphere. like 10 times hotter. and Solar Radiation gets in, so no matter what you do, even if you go under ground, you will get skin cancer from this radiation which will feel like a bad sunburn, and later die.
So over time, with the solar radiation and heat getting in, The planet withered, and died. making it that dry dessert planet. Eventually it regained some sort of atmosphere though, so its a cold dessert ice sphere with 2 polar ice caps and lots of valleys and volcano's.
Life can't be created on mars by "Nuking it". That's so retarded.