Changes

The [[American Civil War]], coming shortly after the [[Industrial Revolution]] in the United States, introduced mechanized warfare to the world with accurate rifles, metal [[warship]]s, [[railway|railroad]] transportation of forces and material, and instant communication via the [[telegraph]].   

The [[American Civil War]], coming shortly after the [[Industrial Revolution]] in the United States, introduced mechanized warfare to the world with accurate rifles, metal [[warship]]s, [[railway|railroad]] transportation of forces and material, and instant communication via the [[telegraph]].   

[[World War I]] (1914-1918) introduced air combat, chemical warfare, [[submarine]] and tank warfare, and the large-scale deployment of the [[machine gun]].   

[[World War I]] (1914–1918) introduced air combat, chemical warfare, [[submarine]] and tank warfare, and the large-scale deployment of the [[machine gun]].   

[[World War II]] (1939-1945) refined tank tactics in the form of the [[Blitzkrieg]], and introduced large-scale strategic bombing of enemy cities. The [[aircraft carrier]] took mastery of the seas.  It ended with the first (and only) use of [[nuclear weapon]]s.

[[World War II]] (1939–1945) refined tank tactics in the form of the [[Blitzkrieg]], and introduced large-scale strategic bombing of enemy cities. The [[aircraft carrier]] took mastery of the seas.  It ended with the first (and only) use of [[nuclear weapon]]s.

   

   

Since the [[Cold War]] began in 1947, there have been a few international wars and many civil wars with outside actors, such as the [[Vietnam War]] and the [[Korean War]].

Since the [[Cold War]] began in 1947, there have been a few international wars and many civil wars with outside actors, such as the [[Vietnam War]] and the [[Korean War]].