The footsoldier is as important now as he was 3000 years ago.
There's only a limited number of missiles, when they're used up, who's going to defend the motherland from the enemy hordes? The ground troops, of course. Nothing will ever replace them, not even the most powerful nuclear bomb; decontamination technology has improved, shelters exist for our vital personnel and hopefully we'll have star wars technology to shoot down the missiles before they even land on our soil. The need for conventional troops is as great now as it has ever been.