US President Joe Biden (L) meets with Defense Secretary Lloyd Austin, Deputy Defense Secretary Kathleen Hicks, Chairman of the Joint Chiefs of Staff General Mark Milley, the Joint Chiefs of Staff and Combatant Commanders in the Cabinet Room of the White House in Washington, DC on April 20, 2022.Mandel Ngan | AFP | Getty ImagesOn Dec. 29, 1940, nearly a year before the Japanese attack on Pearl Harbor would bring the United States into World War II, millions of Americans turned on their radios to hear President Franklin D. Roosevelt explain why the U.S. should support Europe’s forces of freedom against Adolf Hitler’s fascist advance.Americans at the time were deeply uncertain about whether they should be involved at all in the distant European war, though they were aghast at the reports of its horrors. Roosevelt used one of his famous fireside chats to convince them that the U.S. should rapidly and decisively deploy its vast industrial capacity on freedom’s behalf.”We must be the great arsenal of democracy,” he said in the firm, familiar voice that Americans had let into their living rooms for most of that decade. “We have furnished the British great material support and we will furnish far more in the future. There will be no ‘bottlenecks’ in our determination to aid Great Britain. No dictator, no combination of dictators, will weaken that determination by threats of how they will construe that determination.”Eighty years later, President Joe Biden must decide just how far he is willing to go in deploying an updated “great arsenal of democracy” to empower Ukraine to defeat today’s European tyrant, Russian President Vladimir Putin. What Biden’s administration and its partners have done thus far through sanctions and military support has been remarkable, but it remains insufficient as Putin escalates his offensive on Ukraine’s east and south.As U.S. Secretary of State Antony Blinken and U.S. Secretary of Defense Lloyd Austin visit Kyiv today, it is no longer enough for President Biden to argue that the U.S. will defend every inch of NATO territory, as required by all 29 alliance members under Article 5 of its founding treaty. Though that commitment is commendable and crucial for alliance members bordering Russia and Ukraine, it has been construed by Putin as open game on Ukraine itself, which is not a NATO member.It’s now time for President Biden to commit Americans and, to the extent possible, the democratic world more largely to defending Ukraine’s sovereignty, independence, and freedom. That means not only political support and rhetorical common cause but sufficient intelligence and military assistance not just to stalemate Putin but to defeat his ongoing advance. Anything less would be contrary to President Biden’s own stated convictions. As President Biden himself said at his State of the Union address this year, “Throughout our history, we’ve learned this lesson – when dictators do not pay a price for their aggression, they cause more chaos. They keep moving. And, the costs and threats to America and the world keep rising.”Said Biden, “That’s why the NATO Alliance was created to secure peace and stability in Europe after World War II … Putin’s war was premeditated and unprovoked. He rejected efforts at diplomacy. He thought the West and NATO wouldn’t respond. And he thought he could divide us here at home. Putin was wrong. We were ready.”But are we really ready for the next stage, which is growing uglier and more dangerous with each day of Putin’s advance? Only Ukraine’s survival as a free country can begin the reversal of a three-decade downward trajectory of democratic freedoms in Europe and the world, which in turn endangers all the forward progress of Europe since World War II.The newest report by the V-Dem Institute at the University of Gothenburg in Sweden, which produces the largest global dataset on democracy in the world, wrote, “The level of democracy enjoyed by the average global citizen in 2021 is down to 1989 levels,” which means that the last 30 years of democratic advances following the collapse of the Berlin Wall and of the Soviet Union have now been fully reversed.The number of countries that V-dem considers liberal democracies was down to just 34 in 2021, the smallest number since 1995. “Together, autocracies now harbor 70% of the world population – 5.4 billion people,” the report warns.Democracy scholars are tracking disturbing evidence that autocrats are growing bolder. Putin’s full-scale invasion of Ukraine, an independent country led by a freely elected government, followed five military coups in 2021, an increase larger than anything the world had seen in the previous two decades. It sees the dangers increasing as well within established democracies.”Polarization and government misinformation are also increasing,” writes V-Dem. “These trends are interconnected. Polarized publics are more likely to demonize political opponents and distrust information from diverse sources, and mobilization shifts as a result.”In his new book, “The Revenge of Power, How Autocrats are Reinventing Politics for the 21st Century,” Moises Naim writes about the “three Ps” that are driving this trend – populism, polarization and post-truth. He sees this ilk of autocratic power as “malign … incompatible with the democratic values at the center of any free society.”A great deal separates the international situation President Roosevelt confronted in 1940 and that confronted by President Biden in 2022. What connects these two inflection points is the danger of aggressive authoritarianism and the insufficient common cause to confront it.When President Roosevelt spoke in December 1940, his appeal came three months after the signing of the Tripartite Pact among Germany, Italy and Japan, creating a defense alliance of autocracies that was intended to deter the United States from entering the war.On Feb. 4 of this year, the bipartite “Joint Statement of the Russian Federation and the People’s Republic of China” doesn’t seem to go nearly as far, in that it doesn’t commit either side to a defense alliance. But its language is hardly less ambitious and similarly aimed at the U.S. And this time, the two authoritarian great powers are armed with nuclear weapons.”Friendship between the two states has no limits,” reads the 5,300-word text, coming just 20 days before Putin launched his war. “There are no ‘forbidden’ areas of cooperation.”As it was then for President Roosevelt, President Biden now also must weigh the dangers of the moment against the future perils born of insufficient response.”If we are to be completely honest with ourselves,” Roosevelt told Americans, “we must admit there is risk in any course we make take. But I deeply believe that the great majority of our people agree that the course that I advocate involves the least risk now and the greatest hope for world peace in the future.”FDR’s message for Biden is clear: Do more now to stop Putin or pay the consequences later.—Frederick Kempe is the President and Chief Executive Officer of the Atlantic Council.