In his book, “Three Against One,” author Vance Stewart said that after Hitler’s early victories in World War II, his tendency was to underestimate his enemies and overestimate himself.

This is the kind of mentality that can defeat an ego-driven despot.

Before beginning his invasion last week, Vladimir Putin explained how the military incursion was to “denazify” Ukraine. His attempt to justify the operation goes back to 1941 when Ukraine, then part of the Soviet Union, was occupied by Nazi Germany.

At that pivotal time in history, the firm resolve of leaders like Franklin D. Roosevelt and Winston Churchill remained unshaken, inspiring allied nations to stand up to Hitler’s attempt to redraw the map of Europe - and the world - by establishing a Third Reich.

British citizens, following their prime minister, remained unbowed during the daily bombardment of London and when their entire army faced annihilation in northern France before being miraculously evacuated from the shores at Dunkirk by a citizen navy using any vessels available.

The Russians lost an estimated 27 million people during World War II in rising up to defeat the Nazi war machine. In the desperate Battle of Stalingrad, a turning point in the war, Soviet citizens took up arms to support the military, surround and force the surrender of the entire German Sixth Army.

Now the roles are reversed as Russian leader Putin’s invasion has only solidified Ukraine’s sense of national identity. Just before the all-out blitz last Thursday - the biggest attack by one state against another in Europe since World War II - Ukrainian President Volodymyr Zelenskyy, who is Jewish and lost relatives in the Holocaust, called on all citizens to defend the country from the invading Russians. Given a crash course in urban combat, civilian volunteers practiced with cardboard guns, plastic paintball guns or hunting rifles from home as they awaited military weapons.

Vasyl Nikolayevich, a 53-year-old full-time platoon commander in the Territorial Defense Forces, vowed that Ukrainians will fight any invaders like the resistance that fought the Russians in Afghanistan. He speaks from experience. During the 1980s, when Ukraine was part of the Soviet Union, Vasyl fought with the Soviet army against the irregular Afghan resistance forces that finally drove the Soviets out of their land.

Brothers Wladimir and Vitali Klitschko brought Ukraine worldwide fame by winning Olympic medals and becoming heavyweight boxing champions. As the Russian army advanced last week, they quickly made it known that nothing is as important as defending one’s country. Vitali, who has been the mayor of Ukraine’s capital, Kyiv, since 2014, said he was ready to fight.

“I don’t have another choice, I have to do that. I’ll be fighting,” he stated. “I believe in Ukraine, I believe in my country and I believe in my people.”

Both brothers posted a video on social media, calling for action from around the world to stop Russian aggression in their country.

Compelled to enlist in Ukraine’s reserve army earlier this month, Wladimir said the Ukrainians are a strong people who do not want this war but long for sovereignty, peace and democracy.

But Wladimir stated that democracy is a fragile regime and cannot defend itself; it needs the will of the citizens and the commitment of everyone. He also called the current fighting a senseless war that is not going to have any winners.

“Don’t let it continue happening in Ukraine, don’t let it happen in Europe and eventually in the world. United we are strong,” he said.

During their boxing careers, the Klitschko brothers were known as two of the hardest punchers in the history of the heavyweight division. Because of their punishing, battering-ram punches, Wladimir was known as Dr. Steelhammer while Vitali was known by his fans as Dr. Ironfist.

If Putin and his forces overwhelm Ukraine, it will be through superior military force and not any kind of psychological warfare. The Klitschko brothers are prime examples of the inner strength driving the Ukrainian people and their hearts and minds can never be defeated.

By Jim Zbick | tneditor@tnonline.com

The foregoing opinions do not necessarily reflect the views of the Editorial Board or Times News LLC.