You'll be able to make good use of this policy if you plan on raising an army of Tanks, Helicopters, and Modern Armor to crush your opponents in the final eras of the game. It's invaluable when playing as Scythia (who will receive two Helicopters for every one they train) or Genghis Khan (whose light and heavy cavalry units have +3 Combat Strength and a chance to capture enemy cavalry units they defeat).
“Lightning” warfare, better known by the German term blitzkrieg, is a strategy that concentrates motorized forces to create a high-speed breakthrough of an enemy’s lines. Using combined arms and tactical air power, it seeks to keep an enemy off-balance, penetrating deep into the rear and attacking units flanking the breakthrough. The effects could be devastating, especially to morale (soldiers don’t like to be surrounded). Pioneered by Heinz Guderian and perfected by Erich von Manstein and Erwin Rommel, so effective was the blitzkrieg in Poland, France, and Russia that the Soviet Union and Western Allies adopted it to ultimately defeat Nazi Germany.