When did World War II start? An American is entitled to think it started with the attack on Pearl Harbor, as, clearly, the world without the United States is only a world in part.

But ask an Englishman, and he will say the world war began some two years earlier, when Britain declared war on Germany. A Russian will disagree, for much the same reason as the American – what’s the world without Russia? – and for some other reasons as well, some of which, like the Nazi-Soviet Pact or the Nazi-Soviet invasion of Poland, he may think it opportune to forget. An Italian, on the other hand, may well choose to forget the whole thing, especially if remembering it involves deciding whose side his country fought on.

A Chinese may well argue that the war started with the outbreak of the Sino-Japanese War. A Finn will, with every justification, point to the Winter War, which brought Soviet Russia in tandem with Nazi Germany into open conflict with the civilized world. Then an Austrian, a Czech, and a Serb will have had their say, and by and by it emerges that no single answer is sufficiently decisive to be awarded the palm of incontrovertible historical fact.

About a month ago in this space I praised a political observer, Andrei Illarionov, for his astuteness. Well, Illarionov is telling us that we are in the early days of World War IV. Why IV, one might ask. Because the soi-disant Cold War, which the West, for reasons best known to its adversary in that war, decided it had won, was actually World War III.

One can hardly quarrel with this proposition in abstracto. Who says a world war must be hot? Who says every world war must be just like the one before it? If it were, poison gas would have been used under Stalingrad, Dachau would have opened for business in 1916, and an atom bomb would have been dropped on Ankara. To paraphrase Tolstoy’s famous pronouncement about families, while the times of peace in the world are all alike, every world war is different from the next.

Illarionov thinks World War IV began one week ago, on June 12, when a Russian armoured column, moving under the Russian flag, crossed the Ukrainian border and proceeded to Donetsk. (Nobody has doubted that the T-72 tanks that roared through several Ukrainian towns in broad daylight were Russian, except the New York Times, which headlined its story as follows: “Tanks, of Unknown Origin, Roll into Ukraine.”) Until that day, as the gentle reader may recall, Russian troop movements in the region had been covert, while the main instrument of Russian policy since the beginning of the conflict had been men and weapons with no identifiable nationality or origin.

Though in and of itself no more remarkable or noteworthy than the couple of bullets pumped by a “Young Bosnia” terrorist into the emperor’s nephew in June 1914, the open violation of a European frontier in June 2014 by a couple of tanks is none the less something of a watershed. And so, when people look back on our century through the dim mica of history, some of them may well argue that World War IV began on that day.

Especially if they are Ukrainian.