One year after the invasion of Ukraine began, Russia’s reintegration into the world of sports threatens to create the biggest rift in the Olympic movement since the Cold War.

Russia remains excluded from many international sporting events, but that could soon change. Next year’s Paris Olympics are fast approaching and qualifying events are under way. The International Olympic Committee is working to bring athletes from Russia and ally Belarus back into competition, but not everyone agrees.

If Russian athletes are to return to competition, the sports world must resolve two key issues that became clear in the days after the invasion: How can Russian athletes return without alienating Ukrainians? And what can be done about the Russians who support the war?

As the first battles raged, the Ukrainian fencing team refused to compete against Russia at a tournament in Egypt, holding up a sign reading: “Stop Russia! Stop the war! Save Ukraine! Save Europe!”

A year later, one of the biggest obstacles to a Russian return to sports is Ukraine’s insistence it could boycott rather than risk handing its enemy a propaganda success or further traumatizing Ukrainian athletes affected by the war. Other European countries have also spoken of boycotting the Olympics if Russians are allowed to participate.

The last major Olympic boycotts came four decades ago when the United States and more than 60 allies skipped the 1980 Moscow Games. The Soviet Union and its allies retaliated by boycotting the 1984 Los Angeles Olympics.

The actions of specific athletes are a separate issue. Russian gymnast Ivan Kuliak taped a “Z” symbol to his chest, mimicking a marking used on the country’s military vehicles, while standing on the podium next to the Ukrainian winner at an event in Qatar last March. He was banned for a year.

The IOC now says it will not support the return of any Russian athlete who has “acted against the peace mission of the IOC by actively supporting the war in Ukraine,” but hasn’t defined what that means in practice.

Sports organizations took swift action last year in response to the Russian invasion. A day after tanks rolled into Ukraine, Russia was stripped of the right to host the Champions League final in men’s soccer and the Russian Grand Prix in Formula One. After four days, the IOC recommended excluding Russian and Belarusian athletes from events “to protect the integrity of global sports competitions and for the safety of all the participants.”

The Russian men’s national soccer team was in the World Cup playoffs at the time, hoping to qualify for last year’s tournament in Qatar, but Poland refused to play them. Russia was then excluded from the competition — four years after hosting the 2018 tournament and reaching the quarterfinals.

As the Paris Olympics come into view, the IOC has shifted its emphasis to what it says is its duty to avoid discriminating against anyone based on nationality.