The Ukrainian leader's defiance has inspired and shamed the United States and the European Union into going far further -- and far faster -- in turning Russia into a pariah state than it appeared they were ready to go. By promising weapons and ammunition to Zelensky, 44, the West appears increasingly to be drawn into a possible proxy war with Moscow over Ukraine, even though it is not a NATO member that benefits from the bloc's direct mutual defense agreements.

After insisting last week that sanctions would be graded on a rising curve based on Russian behavior, Washington and its allies have now rushed to personally sanction Putin, cut off Russia's central bank from US dollar transactions and kick key Russian banks out of the vital SWIFT global financial network. In the most extraordinary shift, Germany, under new Chancellor Olaf Scholz, has pledged to exceed NATO targets for defense spending and has overcome its reticence to send weapons to war zones by vowing to arm Ukrainians fighting Russia's troops. Germany also halted the Nord Stream 2 pipeline bringing vitally needed Russian gas to Western Europe. In another striking moment, Hungarian Prime Minister Viktor Orban, a Putin protege, has sided with fellow European Union leaders against the Russians. Another autocrat, Turkish President Recep Tayyip Erdogan, who had warm ties with Putin, has invoked a 1930s convention that could complicate Russia's Black Sea naval operations.

And Britain, after long turning a blind eye to oligarch wealth laundered through swank property in London, is belatedly declaring, in the words of Prime Minister Boris Johnson, "There is no place for dirty money in the UK." Even ex-President Donald Trump, who spent last week fawning over Putin's "genius" as the invasion unfolded, felt compelled on Saturday to honor the bravery of Zelensky, whom he once tried to extort using US aid in a telephone call that led to his first impeachment.

The Ukrainian President's heroism has also touched people across the world and set off a torrent of smaller gestures of support. Formula One and European football chiefs have stripped Russia of showpiece events. Russian ballet performances have been canceled in the UK. And some US states are pulling Russian-made vodka off the shelves.

Stateside, 83% of Americans said they favored increased economic sanctions against Russia in response to the invasion, with just 17% opposed, a new CNN poll conducted by SSRS that was released Monday found.

Zelensky's emotional appeal

The significant stiffening of the global front against Russia over the weekend followed increasingly fervent calls by Zelensky for help. European leaders reported that in a call with them last week, he had said he didn't know how long he or his country had left.

Few outsiders expected Zelensky, a former comic actor who, to the frustration of US officials, ignored or downplayed US warnings of an imminent invasion for weeks, would morph into a leader to match this moment in his country's history. His dismissiveness changed a few days before the invasion when he made increasingly heart-rending appeals for help. His earlier reticence may have left many of his countrymen unprepared for the agony that was about to unfold.

Still, under the most extreme circumstances, Zelensky is ironically displaying the very values -- including a staunch defense of democracy -- that would qualify Ukraine for membership in both the European Union and NATO, a path Putin tried to close off with his invasion.

"They are one of us and we want them in," European Commission President Ursula von der Leyen said in an interview with Euronews on Sunday, referring to Ukraine.

Zelensky is not just creating a historic legend for himself, in standing up to tyranny in a manner that places him alongside famed Cold War dissidents like Polish Solidarity leader Lech Walesa and Imre Nagy, the executed leader of the 1956 Hungarian uprising against the Warsaw Pact. He is offering the kind of inspirational leadership that has often been lacking during a pandemic that saw some leaders put their political goals above the public good and refuse to follow the public health rules they imposed on their people. Unlike former Afghan President Ashraf Ghani, who fled Kabul when the Taliban bore down on the capital last summer, Zelensky is resolved to stay and fight -- and possibly to die with his people.

He has become the rarest of leaders -- synonymous with the mood and character of his people at a pivotal moment in history while willing them to ever greater national efforts like British Prime Minister Winston Churchill during World War II or George Washington during and after the American revolution.

In what has already become an iconic comment, Zelensky has rejected American offers of an exit to safety, telling the US, according to his country's embassy in Britain, "The fight is here. I need ammunition. Not a ride."

In another poignant message on Sunday, the Ukrainian President warned the rest of the world that although he and his country were in the firing line, he was waging a fight on behalf of worldwide democracy and freedom.

"Ukrainians have manifested the courage to defend their homeland and save Europe and its values from a Russian onslaught," he said.

"This is not just Russia's invasion of Ukraine. This is the beginning of a war against Europe, against European structures, against democracy, against basic human rights, against a global order of law, rules and peaceful coexistence."

An alarming twist in the crisis

Zelensky's comments came as the Ukraine crisis took an even more alarming turn.

Putin, lashing out at NATO leaders, put Russia's deterrence forces -- including nuclear weapons -- on high alert. The move may have been designed to frighten the West, but it also heightened fears of an escalation to truly alarming levels.

Putin's nuclear rhetoric came as he appeared ever more isolated, with his forces bogged down on the roads to Kyiv and scenes of burned-out convoys hinting at the strength of Ukrainian resistance.

There's never been a greater need for Putin to be provided with some kind of diplomatic off-ramp from the crisis. But neither Western leaders nor Ukrainians have high hopes for talks planned for Monday between officials from Kyiv and Moscow on the border with Belarus.

And Monday's expected crash of the Russian currency, the ruble, on the back of international sanctions could further pile political pressure on Putin and worsen his volatile mood.

A foreboding moment looms

The Russian invasion of Ukraine is, more than anything, the result of one man's obsession with the fall of the Soviet Union, the shape of the post-Cold War world and perceived disrespect for Russia's pretensions as a great power. But if Putin initiated the crisis, it is the behavior of Zelensky that has driven the response of the rest of the world -- often using social media hits that have made the Russian propaganda machine seem flat footed.

But the question must be asked whether the response is all coming too late for Ukraine.

A three-mile-long Russian column was spotted in satellite imagery on the road to Kyiv on Sunday, fueling dread about a possible assault on the capital that would put civilians in the direct firing line and swell the already high civilian death toll, which local authorities put at 352 on Sunday. Western leaders say that it will take time for sanctions to begin to inflict pain on Putin, the oligarchs who support him and the Russian people. But Ukraine may have days, not weeks, left as an independent nation.

The Ukrainian President's survival is taking on more importance for the rest of the world too. The tough slog Russian forces have faced underscores the difficulty Russia would have in subjugating a nation the size of France under occupation. A partitioned Ukraine and a full-scale insurgency would be far more effective with Zelensky as a figurehead. His new influence in global capitals and capacity to mobilize political heat on foreign leaders could be invaluable to the Ukrainian cause, which is why an eventual flight from Kyiv might be essential for his country's hopes of liberation.

But Zelensky and thousands of his fellow Ukrainians know they may be living on borrowed time. Putin appears to be backed into a corner, making it all the more urgent for him to quickly and decisively end the conflict. The Russian leader, who has falsely demeaned Zelensky and his compatriots as Nazis, has a record of scorched-earth responses that pay little heed to civilian losses. Russia's utter destruction of the Chechen capital, Grozny, in its ruthless effort to crush separatists may hold some foreboding omens for Kyiv in the coming days.

And Zelensky's extraordinary success so far is only making him a more valuable target for Russia. Moscow may reason that if he is captured or killed, Ukrainian morale and resistance could collapse.

The evidence of the last few days, however, makes that a questionable proposition.