What If US Army Fought History's Largest Armies?

Coule the US Army Beat History's Largest Armies? The US Army runs about 450,000 active soldiers, backed by Abrams tanks, Apache attack helicopters, and rocket artillery that can hit a target dozens of miles away. That's the most advanced combined arms force on the planet. We're throwing it against eight of the largest armies ever assembled in human history. Ranked smallest to largest, so the numbers only get crazier from here. Max two armies per century. Each army fights at its historical peak. No upgrades, or time travel. Let's start!