Combined Arms

 

"Ukraine hopes that its counteroffensive will end this stalemate. . . .  The troops have learned a technique known as combined-arms warfare, in which different parts of the military work together to take territory. Tanks punch through enemy lines by rolling over trenches, for example, and infantry then spread out to hold the area."  from The NY Times. I have read that combined arms warfare is how Grant won the Civil War, by the way, inventing modern strategy and tactics. That is why Grant (not Lee) is studied in military institutions, except in Russia, apparently.