Except WW1, WW2, Korea and Vietnam were all very costly and direct engagements. US involvement in foreign affairs skyrocketed because WW1/WW2 destroyed Europe and created a power vacuum that we were eager to fill. If we didn't have these smart bombs we would just be involved in fewer but more bloody global conflicts.
The comparison is not between "do it without smart bombs and drones" vs "do it with smart bombs and drones" and the former costing more.
The comparison is between "if we didn't have the smart bombs and drones, we wouldn't have done anything because whatever it was wouldn't have been worth the cost in money and American lives" versus "we spent a million dollars blowing up some stuff because we could do it on the cheap and with no risk."
On a broader scale the US's involvemnt in the foreign affairs of other nations skyrocketed when we went from having volunteer armed forces to a "professional" armed forces. Ike predicted as much in his rant about the military-industrial complex.