St. Petersburg, Russia (CNN) Among the world leaders who joined Queen Elizabeth II and other heads of state to commemorate the 75th anniversary of D-Day, one was conspicuously absent: Russian President Vladimir Putin.

At first glance, that makes sense: The Soviet Union did not take part in Operation Overlord, the massive amphibious invasion that laid the groundwork for the liberation of western Europe in World War II.

But Putin has attended in the past. In 2014, he attended the 70th anniversary of the 1944 Allied landings. Asked on Thursday why he was not invited, Putin dismissed the suggestion that he was deliberately snubbed.

"As to whether I was invited or not, we also do not invite everyone to every event," Putin said. "Why do I have to be invited everywhere to some event? Am I a wedding general, or what? I have enough of my own business. This is not a problem at all."

But Putin also used the question to draw attention to a longstanding Russian grievance: The perception that the Soviet population's massive sacrifices in World War II have been somehow overlooked in the West.

"As for the opening of the Second Front, I draw your attention to the fact that this is the Second Front," Putin said, referring to the Normandy landings. "The first was with us. If you count the number of divisions, the strength of the Wehrmacht [the German army] who fought against Soviet troops on the Eastern Front, and the number of troops and equipment that fought on the Western Front from 1944 on, then everything will be clear."

Photos: The Allied invasion of Normandy American troops storm the beaches of Normandy, France, on June 6, 1944. Hide Caption 1 of 18 Photos: The Allied invasion of Normandy The British Army's 50th Infantry Division lands on beaches in Normandy. Hide Caption 2 of 18 Photos: The Allied invasion of Normandy Four Americans show off their shaved heads, which spell out the word "hell," a few hours before arriving on the beaches of France. Hide Caption 3 of 18 Photos: The Allied invasion of Normandy US troops wait to disembark a landing craft on D-Day. The Allies went to elaborate lengths to maintain secrecy and mislead Adolf Hitler. They employed double agents and used decoy tanks and phony bases in England to hide actual troop movements. Hide Caption 4 of 18 Photos: The Allied invasion of Normandy US paratroopers fix their static lines before a jump over Normandy on D-Day. Hide Caption 5 of 18 Photos: The Allied invasion of Normandy US troops huddle behind the protective front of their landing craft as it nears a beachhead in France. Smoke in the background is naval gunfire giving cover to troops on land. Germans rained mortars and artillery down on Allied troops, killing many before they could even get out of their boats. Fighting was especially fierce at Omaha Beach, where Nazi fighters nearly wiped out the first wave of invading forces and left the survivors struggling for cover. Hide Caption 6 of 18 Photos: The Allied invasion of Normandy Tank landing ships, each towing a protective barrage balloon, leave the English coast carrying supplies to the French beachhead. Hide Caption 7 of 18 Photos: The Allied invasion of Normandy US troops and vehicles are ready to disembark. Hide Caption 8 of 18 Photos: The Allied invasion of Normandy Commandos with the British Royal Navy's 4th Special Service Brigade advance to Juno Beach. Hide Caption 9 of 18 Photos: The Allied invasion of Normandy US Gen. Dwight D. Eisenhower, supreme commander of the Allied forces, gives the order of the day to paratroopers in England. "Full victory — nothing else" was the command just before they boarded their planes to participate in the first wave. The invasion — code-named Operation Overlord — had been brewing for more than two years. Hide Caption 10 of 18 Photos: The Allied invasion of Normandy Landing craft and a fleet of protection vessels approach Omaha Beach. Hide Caption 11 of 18 Photos: The Allied invasion of Normandy American troops help their injured comrades after their landing craft was fired upon. Although the true number of casualties on D-Day will never be known, it is estimated that approximately 10,000 Allied soldiers were killed, wounded and or were missing in action. Hide Caption 12 of 18 Photos: The Allied invasion of Normandy Allied soldiers arrive on a beach. Hide Caption 13 of 18 Photos: The Allied invasion of Normandy These US soldiers reached Omaha Beach by using a life raft. Hide Caption 14 of 18 Photos: The Allied invasion of Normandy French soldiers arrive after Allied forces stormed the beaches of Normandy. Hide Caption 15 of 18 Photos: The Allied invasion of Normandy Injured American soldiers wait to be moved to a field hospital after storming Omaha Beach. Hide Caption 16 of 18 Photos: The Allied invasion of Normandy This aerial photo shows a landing zone for British planes near Ranville, France. Hide Caption 17 of 18 Photos: The Allied invasion of Normandy Canadian soldiers place flowers on temporary graves for allied soldiers in Normandy. Hide Caption 18 of 18

Demise of Communism

The war on the Eastern Front, known in Russia as the Great Patriotic War, took a horrific toll, costing the Soviet Union more than 25 million military and civilian lives -- more than any other country lost during the war. The war against Nazi Germany, in the Russian view, ended decisively with the fall of Berlin to the Red Army in 1945.

It's a touchy subject for Russia. Veneration of the Soviet war dead has been elevated to something approaching a secular religion in Russia, particularly after the collapse of the USSR and the demise of Communism as a guiding ideology.

But the past isn't past for Russia. The long shadow of World War II still hangs over Russia's foreign policy.

In comments ahead of the D-Day commemorations, Russian Foreign Ministry spokesperson Maria Zakharova took a swipe at the ceremony, saying: "The Normandy landings were not a game-changer for the outcome of WWII and the Great Patriotic War. The outcome was determined by the Red Army's victories -- mainly, in Stalingrad and Kursk. For three years, the UK and then the US dragged out opening the Second Front."

Picture taken during the winter of 1942-43 shows Soviet soldiers driving out the German army during the Battle of Stalingrad, a major turning-point in the Allied victory over Germany during World War II. The battle, lost in February 1943 by the Germans, cost 70,000 German lives and yielded 91,000 prisoners-of-war to the Russians.

Zakharova's remarks drew immediate condemnation.

"The USSR bore the brunt of the fight +lost 20 million people!" wrote retired US Ambassador (and former State Department spokesperson) Nicholas Burns on Twitter. "It was the key ally. The U.S. sent significant supply of planes, tanks+munitions to the Red Army. But simply wrong for Moscow to discount the heroism of our soldiers on D-Day—a turning point of the war in the West."

The USSR bore the brunt of the fight +lost 20 million people! It was the key ally. The U.S. sent significant supply of planes, tanks+munitions to the Red Army. But simply wrong for Moscow to discount the heroism of our soldiers on D-Day—a turning point of the war in the West. https://t.co/prAt4to0t7 — Nicholas Burns (@RNicholasBurns) June 5, 2019

Steven Pifer, the former US ambassador to Ukraine, was more cutting.

"Let's see. Why was Putin not invited to D-Day commemoration?" he wrote on Twitter. "Is it: (A) Red Army played no part in Normandy invasion (B) Russia today conducts low-intensity war against its neighbor, having made biggest land grab in Europe since WW II I'm going with: (C) Both of the above."

Let's see. Why was Putin not invited to D-Day commemoration? Is it:

(A) Red Army played no part in Normandy invasion

(B) Russia today conducts low-intensity war against its neighbor, having made biggest land grab in Europe since WW II

I'm going with:

(C) Both of the above https://t.co/aFzocHt9ep — Steven Pifer (@steven_pifer) June 6, 2019

Pifer here was referring to the annexation of Crimea in 2014 by Russia, a move many world leaders have seen as a dangerous break from the post-war order in Europe after 1945 -- and one that for some appeared to have historic parallels with Hitler's annexation of the Sudetenland in 1938, a prelude to World War II.

That may seem like ancient history, but Russia keeps replaying it. Zakharova has dedicated considerable time in her briefings decrying the "Munich betrayal" -- the 1938 agreement ceding the Sudetenland to Germany. Highlighting the piece of paper that UK Prime Minister Neville Chamberlain waved on returning from Munich presents a convenient counter-argument: It allows Russia to gloss over the Molotov-Ribbentrop pact, the nonaggression pact between Hitler and Stalin that paved the way for the German invasion of Poland in 1939 and the Soviet invasion a few weeks later.

In short, the memory and massive sacrifice of World War II is still a way for Russia to claim the moral high ground both in current affairs.