The dissolution of the Soviet Union, Russian President Vladimir Putin told his nation, "was the greatest geopolitical catastrophe of the 20th century."

That was in 2015. Putin was wrong then. And he was wrong this week to describe Ukraine as a country "created by Russia" in a rambling, revisionist speech in which he aired his grievances with his western neighbor and the West in general.

In fact, Ukraine is a sovereign nation recognized by the United Nations and recently by Russia itself, until Putin's warped rewrite of history. And Russia is not deploying "peacekeepers" to Ukraine: It's invading by sending troops to eastern regions in what represents just the latest attack on Ukraine's sovereignty.

"Countries ask for peacekeepers to come in or the U.N. negotiates with the country to put peacekeepers in," U.S. Rep. Betty McCollum, D-Minn., told an editorial writer this week. "This was Russia creating its own mischief as an excuse to bring their troops in."

McCollum was part of a bipartisan, bicameral congressional delegation that attended the recent Munich Security Conference, which saw Western allies united in defiance of Russian aggression. That includes its 2014 illegal annexation of Crimea; its support of Russian separatists in eastern Ukraine; its similar separatist recognition and occupation of parts of Georgia; its attack on America's 2016 presidential election, as well as cyberattacks, disinformation campaigns and the rescue of the homicidal Assad regime in Syria.

The latest aggression, intended to aggravate the Ukraine crisis, was Russia's recognition of the so-called Donetsk and Luhansk People's Republics, two breakaway regions that are part of a grinding conflict in eastern Ukraine that has already killed more than 14,000 people. Both "republics" claim more territory than they control, setting up a potential direct fight between Ukraine and Russia over the region. Whether Russian forces would stop there, or extend westward to capture the capital, Kyiv, has the world waiting.

But appropriately, Western nations including the U.S. aren't waiting to respond. On Tuesday President Joe Biden imposed what he called a "first tranche" of sanctions on two major Russian banks and five key individuals and their families, as well as a ban on secondary trading of Russian sovereign debt. (A day earlier Biden sanctioned activity directly related to doing business with the breakaway republics.)

The European Union and Britain imposed a first round of sanctions, too, and all Western entities warned of more dire penalties if Russia goes further. Most impactfully and impressively, Germany, after sending unsure signals, declined to certify the Nord Stream 2 natural-gas pipeline that originates in Russia.

The allies have seemingly coalesced around multiple rounds of sanctions, depending on how far Russia presses its invasion. While arguments can be made that maximum sanctions should be imposed now, unity and coordination within the West is paramount and helps blunt Putin's bid to split the alliance.

The imperative of unity was clear in Munich, McCollum said. "I never felt such solidarity between the democracies on something as I did in the last two days of Munich," she said, later adding: "We are going to show them there is no daylight between any of the democracies on these sanctions."

The stakes couldn't be higher, John Herbst, a former U.S. ambassador to Ukraine who is now senior director of the Atlantic Council's Eurasia Center, told an editorial writer.

"We've created an order after World War II, and again reinforced at the end of the Cold War, that produced extraordinary stability," Herbst said. "If you want to tear up that order and let countries by fiat take land from their neighbors, impose their will on their neighbors, you are opening the door to a much more dangerous world than one we've lived in for 70-plus years."

Putin, along with his increasingly close fellow despot Xi Jinping, the president of China, wants to tear up that order, with Putin attempting to revert to a mid-1990s European security order. He fails to acknowledge that his own behavior necessitates a more forward NATO posture in Eastern Europe — something Biden pledged to bolster in his sanctions announcement on Tuesday.

The reinvigorated transatlantic unity won't be as effective if it is undermined on the Potomac. Political partisanship is normal. Paralysis is not. If the Beijing-Moscow entente heralds an axis of autocracy, Washington needs to show that democracy, however difficult, still works.

"What the Chinese and the Russians have been saying to other countries is, 'See, democracies don't work because they can't get their affairs in order,' and we have to show as a democracy we can get our affairs in order," McCollum said.

That will mean some sacrifice at home. Biden has made it clear that although U.S. forces will not fight in Ukraine, there will be an economic cost. And while the turbulence won't be as harsh as in Europe, prices on energy, among other components of a complex economy, are likely to continue to rise.

Biden termed recent Russian developments as "the beginning of a Russian invasion of Ukraine." For the U.S. and its allies, however, Putin's actions signal the continuation of what began as Soviet aggression. Defending democracy, here at home and in like-minded nations, is critical. Indeed, not standing up to Russia now could lead to a 21st-century catastrophe.