But the 21st century is not the 20th century. When Polish communists, backed by Soviet communists, falsified the results of a national referendum in 1946, there weren’t many international observers around to complain. In the past few days, by contrast, the Internet has lit up with photographs of “pro-Russian activists” carrying Russian-made RPGs, as well as audio clips of Russians barking orders. The effect of these revelations, however, has been to encourage the Russians to lie more brazenly and aggressively. The Russian foreign minister continues to insist that Moscow is not interested in destabilizing Ukraine, and Vladimir Putin has called on the U.N. to condemn Ukraine’s weak and confused attempts to defend itself. Russian television—watched by many in eastern Ukraine—continues to denounce nonexistent violence coming from “fascist Kiev” and is even showing politicized weather reports: Dark clouds are gathering over Donetsk while there is sun in Crimea. These language games and disinformation campaigns are now far more sophisticated than anything the Soviet Union ever produced.

This combination—old-fashioned Sovietization plus slick modern media—is genuinely new, so much so that it’s fair to say we are witnessing a new kind of war, and a new kind of invasion. Thirteen years ago, in the wake of 9/11, the United States suddenly had to readjust its thinking to asymmetric warfare, the kinds of battles that tiny groups of terrorists can fight against superior military powers. We relearned the tactics of counterinsurgency in Iraq.

But now Europe, the United States, and above all the Ukrainians need to learn to cope with masked warfare—the Russian term is maskirovka—which is designed to confuse not just opponents, but the opponents’ potential allies.