The biggest military victories of the 21st century didn’t look like people expected. Consider Russia’s seizure of Crimea from Ukraine, which relied upon not fighter jets or advanced warships but crafty public relations, Special Forces, and a proxy army. How did Russian President Vladimir Putin do it? He started with outreach to aggrieved Russian-speaking people in Crimea, posing them as victims of the crooked Ukrainian government. Russian state media and social media flooded the region and the world with propaganda. Putin then encouraged militias to form. They seized an airport, military bases, and government buildings. A parliamentary vote declared Crimea would secede from Ukraine. A referendum, days later, voted the region to become part of Russia. It was a new kind of invasion, and it worked.