I don't know what will be used in the next world war, but the 4th will be fought with stones.

Summary

This quote suggests that the advancements in technology and weaponry in past world wars have continuously escalated the extent of destruction. It implies that future conflicts will revert back to more primitive methods, such as using stones as weapons, due to the devastation caused by sophisticated warfare. The quote may also serve as a commentary on the cyclical nature of wars, symbolizing how civilization can regress despite progress made in other areas.