A new era of high-tech war has begun

Big wars are tragedies for the people and countries that fight them. They also transform how the world prepares for conflict, with momentous consequences for global security. Britain, France and Germany sent observers to the American civil war to study battles like Gettysburg. The tank duels of the Yom Kippur war in 1973 accelerated the shift of America’s army from the force that lost in Vietnam to the one that thumped Iraq in 1991. That campaign, in turn, led China’s leaders to rebuild the People’s Liberation Army into the it is today.