As technology becomes increasingly sophisticated, technology is likely to play an even greater role in the "war on drugs" than is presently the case. Previous answers have already mentioned a number of specific examples of the use of technology in the attempt to prevent importation of illegal drugs into the United States.
It is easy to imagine how drone aircraft might be used in such efforts even more than is already the case. Drones have been highly effective in the war against specific terrorists in Afghanistan and Pakistan, and it is easy to imagine how they might be used to patrol the borders, spot smugglers at sea, disable boats, etc., etc.
"Nano" technology is also likely to be increasingly used. I've read recently about flying cameras the size of bees that are almost indistinguishable (at a distance) from insects. (These are not examples of "nanotechnology in the precise sense of the word, but they are moving in that direction.)
It would not surprise me if someone, somewhere, is working on some kind of pesticide designed to kill opium plants without harming humans, animals, soil, water, or other crops. In short, technology is likely to be increasingly employed to fight drugs and drug smuggling, although smugglers and users can be expected to employ counter-measures as well.
See links below.