How a Russian invasion of Ukraine could trigger a chain reaction of reprisals

We've been given early warnings of the damaging chain reaction we can expect in the tit-for-tat of international economic retaliation should Russia re-invade Ukraine.

The U.S. promises a swift retort: crippling sanctions on Russian banks, energy firms, oligarchs, and even family members of Kremlin insiders. A Russian counter-response is anticipated: American politicians warn about the possibility of cyberattacks and higher gas prices.

Europeans are particularly vulnerable as they depend on fuel from Russia to heat their homes, and any supply disruptions could worsen already-high gas and oil prices.

The cyberattacks may already have begun; Ukraine blames Russia for hacks that have knocked its defence ministry and banks offline.

U.S. President Joe Biden acknowledged the risks ahead in a speech Tuesday, where he delivered warnings both to Russia and to his own people.

To the Russians, he vowed to counter cyberattacks on any key U.S. infrastructure, which, as Americans discovered last year with the Colonial pipeline hack, can disrupt the country.

To his own country, Biden prepared it for economic blowback.

"I will not pretend this will be painless. There could be an impact on our energy prices," said Biden, adding that he was working with fuel producers to mitigate the impact. 

"The American people understand that defending democracy and liberty is never without cost."

Biden has made clear U.S. troops would not enter the fight. His stance has broad though not total support in U.S. politics, as most Washington Republicans and Democrats agree with him. 

Sen. Bernie Sanders says there must be consequences if Putin launches the biggest European land invasion since the Second World War.

But he added, in an interview with NPR: Prepare for Russian retaliation, possibly against banks, energy companies and the food industry.

"Let's be realistic. We should do [sanctions]. I think there's no alternative. But when you do that, what do you think Russia's going to do?" Sanders said. 

"[They won't be saying], 'Oh, that's fine, we're not gonna do anything.' I think there will be a response."