My countrymen often say that Russia is a country with an unpredictable past. It’s true: Our history is often rewritten to match the political agenda and casual whims of those in power.

That mentality is especially evident during the annual celebrationshonoring the Soviet Union’s victory over Nazi Germany in 1945, when a carnival-like hysteria takes over the country. There are military parades in the streets, commemorations, concerts. Kindergartners dress up in military uniforms. Officials pin on the black and orange ribbon of St. George, a symbol of remembrance.

Russians call all this “pobedobesie,” or “victory frenzy.” Soviet accomplishments are front and center, and the undesirable parts of the war — from Joseph Stalin and Adolf Hitler’s collaboration at the beginning of the conflict to America’s military victory over Japan — are stripped away.

Even the chronology of World War II is subject to revision. For the rest of the world, the war began on Sept. 1, 1939, but in Russia, the Great Patriotic War, as it is referred to, started when Hitler launched an attack on the Soviet Union and ended on May 9, 1945, with Nazi Germany’s capitulation, rather than with the formal surrender of Japan later that year.

Accentuating Soviet accomplishments during the war is a way for the government to give Russians what they most passionately crave after the painful humiliation of losing the Cold War: national pride. Polls consistently show that history is the main source of pride for many Russians. ...