"Three years into the Russian aggression, we have experienced every Kremlin method and technique there is," Ukrainian President Petro Poroshenko told The Daily Signal.

"And I should remind that Moscow started its campaigns in Crimea and eastern Ukraine particularly with the subtle manipulation of information," Poroshenko said. "Tanks, artillery, and hundreds of innocent victims followed later."

In Ukraine, Russian military forces have combined World War I and II-era weapons and tactics—like artillery bombardments, tank attacks, and trench warfare—with weapons unique to the 21st-century battlefield, such as cyberattacks and sophisticated propaganda campaigns geared toward TV and internet audiences.

Видео дня

In September 2014, U.S. Gen. Philip Breedlove, then NATO’s top commander, called Russia’s hybrid war in Ukraine "the most amazing information warfare blitzkrieg we have ever seen in the history of information warfare."

"Fake news is a weapon," Viktor Kovalenko, a Ukrainian journalist and army combat veteran from the 2015 battle of Debaltseve, told The Daily Signal.

Read alsoSBU General says Putin sought to seize Ukraine in 3 stages"I saw firsthand how Russians use fake news against the Ukrainian troops on the front line," Kovalenko, a former professor of journalism at the Taras Shevchenko National University of Kyiv, added. "Via fake news Russians wanted to defeat Ukrainians the same way, effectively, as by artillery and tanks."

Hybrid warfare is Russia’s modern interpretation of a Soviet military doctrine called "deep battle," in which military operations extend beyond the front lines deep into an enemy country’s territory in order to hinder its ability to wage war.

Read alsoReports suggest Russia engages in psychological warfare in Avdiyivka - mediaAnd, some say, Russia is tapping into its hybrid warfare arsenal, now battle-tested in Ukraine, to wage a uniquely 21st-century style of war against the United States and the European Union.