Napoleon's military success stemmed not from inventing new ways of war, but from mastering the available tools and concepts of his era to a degree his opponents had not. This historical lesson serves as a warning for the modern US, whose slow adaptation to existing threats like drones suggests it is failing to master the current military landscape.

After Cannae, Rome couldn't defeat Hannibal in open battle, so they adopted a strategy of avoidance, creating a stalemate. For a power on the brink of collapse, simply surviving is a form of victory. This prolonged timeline allowed Rome to regroup, rebuild its manpower, and ultimately go on the offensive.

Joan's success relied on an "infectious bravery" that inspired demoralized troops and overrode the caution of veteran commanders. She consistently pushed for aggressive attacks when professionals advised delay. This highlights how a leader's conviction and confidence can become a tangible strategic advantage, transforming a unit's psychology and capacity for risk.

In conflicts, a critical error is to believe that escalating pressure will automatically force an opponent to back down. This overlooks that for the adversary, the fight may be existential, leaving them no room to retreat and thus leading to a more dangerous conflict.

While most WWI belligerents framed their involvement as a defensive necessity for "Hearth and Home," Italy was transparently opportunistic. Its leaders openly admitted they were not defending themselves but attacking for conquest and glory, making it arguably the most acquisitive campaign of the war.

Military technology often evolves incrementally. However, a breakthrough like the Maxim machine gun can suddenly render centuries of established doctrine—such as the drilled infantry charge—completely obsolete. This creates a strategic crisis that forces an equally radical technological and tactical response, like the tank.

The narrative of incompetent generals is too simplistic. They faced a novel military challenge—defensive technology like machine guns and trenches massively outpaced offensive tactics. Their deadly "experiments" were desperate attempts to solve a problem with no known answer, not just callousness.

The Allies built their trenches as temporary offensive launch points. In contrast, the Germans, adopting a defensive "what we have, we hold" strategy, built deeper, safer, more comfortable trenches with reinforced concrete, reflecting their long-term strategic outlook.

Contrary to expectations of a high-tech war, the conflict in Ukraine demonstrates enduring principles of warfare. The superiority of defense over offense, the difficulty of breakthroughs without air power, and the tendency toward attrition are all classic lessons that would be recognizable to strategists from past major conflicts.