They had 'smart' versions of bombs and missiles back in 91. They just didn't have GPS guided ones/cheap guided munitions. They have both now (with cheap in a relative term).
To be specific, the relatively cheap GPS-guided bombs that became available after the 1991 Gulf War consisted of new electronics and new tail sections bolted onto ordinary "iron" bombs manufactured many years earlier.
The US seems to have started using concrete bombs in 1999 (against Iraq, but not during either gulf war).
http://www.nytimes.com/1999/10/07/world/us-wields-defter-wea...