One interesting comment concerning "Smart bombs", it appears that they were in use in SEA...but probably not as technically advanced as the current crop...
From the book: THE PRICE OF EXIT by Tom Marshall.
"From 1965 to 1968 the U.S. Navy and Air Force lost ninety-seven aircraft unsuccessfully attempting to bring down the bridge at Thanh Hoa, the primary rail connector to China, which was the source of supplies and safe havens then just as it had been against the French. The Thanh Hoa was destroyed on the first run in December 1972 by a single, "smart" two-thousand pound bomb."