With more than 100,000 Russian troops hovering on the borders of Ukraine and believed to be ready to invade, the siblings who won fame and considerable fortune as enduring and mighty heavyweight champions just a few years ago have publicly committed themselves to defending their homeland.

The 45-year old Wladimir, the younger of the two, has even enlisted in the Ukrainian army amid the escalating tensions which are threatening world peace.

And big brother Vitali, 50, now the Mayor of the Ukrainian capital, Kyiv, says he will himself take up weapons, stand his ground and fight to the death if necessary.

Some Western powers, including Britain, believe an invasion similar to that in which Russia annexed Crimea, may be imminent; others suggest Putin will delay sending in his massed militia until after the current Winter Olympics so as not to upstage his friend Xi Jinping, the similarly autocratic Chinese leader.

Wladimir, who lost his titles to Britain's Tyson Fury and was later also beaten by fellow Olympic champion Anthony Joshua, also British, enjoyed a decade of dominance. He won the Olympic super-heavyweight gold medal in Atlanta in 1996, replacing his brother in the Ukrainian team after Vitali had failed a drugs test when it was found he had used a steroid substance on an injured knee.

Although they were born in Kazakhstan of Soviet parents, both were brought up in Ukraine where their father was a major in the Soviet Air Force.

They have also lived in Russia and based their boxing careers in Germany, but now they are resident in Ukraine again with their families.

"I could not stand by and do nothing,'' Wladimir told CNBC. "The situation is serious and could escalate to an all-out war. I love my country which is why I have signed up as a reserve for the territorial force.

"We are strong. This will be a very painful price for everyone. We hope the situation can be solved by diplomacy but if not we have to take weapons in our hands and defend our country."

Fighting talk, if somewhat different from that used to hype up tensions in their notable boxing days when Vitalii, aka "Dr Ironfist", and "Dr Steelhammer" Wladimir ruled the rings, holding every version of the professional heavyweight crown between them.

I have always admired the erudite and engaging Klitschkos as boxers and esteemed noble artists in every sense. They surely are the most cultured personalities the fight game has ever produced, both holding PhDs in sports science and fluent in four languages, including Russian.

Giants indeed, with Vitali standing 6 foot 7 inches and his brother just an inch shorter.

After he retired in 2013, Vitali turned to politics full time and was elected mayor of Kyiv a year later. Since then he has always been a central figure in Ukrainian politics and tipped to be the country’s leader eventually. But it all depends on whether Ukraine can keep Putin at bay.

The power-punching Vitali, the only heavyweight boxer to have reigned as a heavyweight champion in three different decades, won praise for the way he kept Kyiv in the game in another big fight - against COVID-19.

He has been vocal in asking Western powers to supply weapons to offset the huge military advantage Russia has over its neighbour and former satellite. He recently described Germany’s offer of 5,000 second-hand helmets as "a joke".

A keen student of geopolitics he says of the Russian President, who some would call a dictator: "Mr Putin’s idea is to rebuild the Soviet empire. We don’t want to go back to the USSR, we see our future as a democratic European country. This is why we have to fight. We have no choice..."

So as sport yet again merges into politics many will wish boxing's Twin Towers well and hope that, if a Russian push comes to shove, their counter-punching can help give Putin a bloody nose.