Russia's war of aggression against Ukraine is about to enter its third year. There is much to feel good about, but there are also grounds for worry. In short, it is time to take stock.

What Ukraine and its Western backers have accomplished in the wake of Russia's February 2022 invasion is extraordinary. Russia, a nuclear-armed power with three and a half times the population of Ukraine, ten times the GDP, and a military with many times the personnel and equipment, has been fought to something close to a draw. Ukraine controls some 80% of its territory, much as it did two years ago.

Russian President Vladimir Putin obviously calculated that his war of conquest would resemble his previous invasion of Ukraine in 2014, when Russian forces swept in and quickly seized Crimea and much of the eastern Donbas region. He saw Ukraine, Europe, and the United States as weak and divided. He also believed his generals when they promised that Russia's military was strong and would overwhelm whatever resistance Ukraine could muster.

All these assumptions have been proved wrong. But there is reason to be concerned nonetheless.

Ukraine's highly anticipated counter-offensive, designed to liberate territory and deliver a battlefield win or at least momentum that would set the stage for promising diplomacy, was largely rebuffed. Russia has learned to live with Western economic sanctions and has largely rerouted vital energy exports to China and India.

Western military sanctions have likewise been evaded: Russia has continued to sell weapons to India and others and buy them from North Korea and Iran. It has also been able to purchase ostensibly civilian technology and products that can be repurposed for military use. It has expanded its defense industrial base and now has a sizeable advantage over Ukraine in the quantity of artillery and ammunition that it can deliver to the battlefield.

Russia shows few signs of exhaustion. Despite the extraordinary human toll of the war, estimated to be more than 300,000 Russian troops killed or injured, Putin's control of the media and public narrative has allowed the Kremlin to minimize dissent and persuade many Russians that their country is the victim rather than an aggressor.

Meanwhile, Ukraine is showing signs of political division. Ukrainian President Volodymyr Zelensky just fired his top general. More important, Ukraine is struggling on the battlefield, largely owing to Republicans in the US Congress blocking a $60 billion military assistance package. Republican opposition appears to reflect a mixture of resurgent isolationism, sympathy for the authoritarianism of Putin, and a partisan desire not to hand President Joe Biden a political victory before the presidential election in November.

Ideally, Biden will be able to convince enough Republicans to work with him and fellow Democrats to approve a new tranche of assistance, which is in America's strategic interest. But this outcome cannot be counted on, despite growing evidence that Ukraine is running short of arms and ammunition and, as a result, experiencing mounting difficulty in standing up to Russian military pressure.

This raises the question: How might Ukraine and its friends in Europe and elsewhere fill at least some of the void left by a US no longer prepared to offer significant levels of assistance?

Europe has already agreed to provide Ukraine with more than $50 billion in new economic aid; together with others (such as South Korea and possibly Japan), a coordinated plan is also needed to provide Ukraine with arms and ammunition so it can better defend itself and strike important Russian military targets. At the same time, Ukraine's friends must help it reconstitute and expand its arms industry, so that it becomes less dependent on the ability and willingness of others to provide the resources the war effort requires.

At the same time, Ukraine can reduce its resource needs and save lives by adopting a largely defensive military strategy. Protecting and preserving the 80% of the country Ukraine now controls is feasible and essential. Ukraine would not be giving up anything by embracing such a posture, given that military liberation of Crimea, Donbas, and other Russian-occupied areas is not in the cards, at least in the short term. And it can continue to seek full territorial restitution at the negotiating table if and when serious talks commence.

If the provision of arms will determine how Ukraine fares this year, the US presidential and congressional elections in November will go a long way toward determining how it fares in 2025 and beyond. If Biden is re-elected, and if the US Senate flips to Republican control, as many expect, but the Democrats retake the House of Representatives, then the stage will be set for renewed US economic and military aid and possibly a tie between Ukraine and NATO. This would disabuse Putin of the view that time is on his side, in turn increasing the odds that diplomacy would come to the fore.

If, however, former President Donald Trump wins and the Republicans maintain control of the House of Representatives, Ukraine will face a far more difficult future. The burden of Ukraine's security would fall even more on itself and its friends in Europe and Asia. If they prove willing and able to fill much of the gap left by a withdrawal of US support, one could envision a prolonged stalemate on the battlefield followed by constructive diplomacy. If not, Putin would be likely to press his advantage on the battlefield and come to the negotiating table only to impose the outcome he has sought from the beginning.

The difference between these two futures is stark. The stakes for Ukraine, for Europe, and for the world are enormous. Chinese President Xi Jinping, with his own designs on Taiwan, is watching with keen interest how this plays out. So, too, is Iran. If the US proves unwilling to meet its obligations and uphold the rule of international law that territory may not be acquired by force, we are looking at a future far more violent and dangerous than the past.

From Project Syndicate