What is the effect of changes in maritime technology (including military innovations) on global interactions?

Accurate portable timekeeping (marine chronometers) in the 18th century made it possible for a navigator to know longitude with certainty. The transition from sail to steam propulsion in the 19th century made sea transportation independent of seasonal wind patterns. The use of radio and later satellite GPS systems in the 20th century made navigation much more exact, not subject to local magnetic variations.