The Iraqis were using Russian-built GPS jammers in an attempt to hinder the Coalition's war effort. The GPS jammers have little to no impact on bombs for several reasons. 1) Our military believes in redundancy and has several backups for bomb and missile guidance. 2) The jamming has little to no impact on military assets high above the ground; they can still pick up the GPS signal from the broadcasting satellites. Even if bombs lose the signal on the way down, their backup systems can easily keep them on target.
However, the jammers hinder (or eliminate) the usefulness of GPS receivers at ground level. This was not appreciated by the US military as there are many, many uses for ground-based GPS. This is why the US forces reportedly destroyed all of the GPS jammers.