How advanced is our military technology compared to other countries?

I was having a conversation with my step father about how I heard we have the most advanced military technology in the world. Then he went about saying how the Iraqis and Afgans have some explosive technology that even us Americans cannot comprehend. For instance, the phone call bomb detenotion and explosive marbles. Is it true that our scientist can't figure out how to develop these kinds of clever explosive devices?