Wimbledon has banned Russian and Belarusian players from this year's event in June, the All England Club announced Wednesday.

Why it matters: Wimbledon, the oldest and most prestigious tennis tournament in the world, hasn't barred athletes from specific countries since the aftermath of World War II.

• Four Russian men are ranked in the ATP top 30, including No. 2 Daniil Medvedev, the reigning U.S. Open champion.
• Five Russian women are in the WTA top 40, and Belarus has two in the top 20, including No. 4 Aryna Sabalenka, a 2021 Wimbledon semifinalist.

The backdrop: After the war began in February, Russia and Belarus were quickly barred from team events like the Davis Cup and Billie Jean King Cup, both of which were won by Russian teams in 2021.

• Individual players from Russia and Belarus have continued to play, though they haven't had flags or countries listed next to their names.
• Last month, British Sports Minister Nigel Huddleston suggested that Medvedev and his fellow Russian players might need to provide "assurances" that they don't support Russian President Vladimir Putin.

What they're saying: Some in the tennis community have been calling for a full ban, while others argue that Russian and Belarusian athletes — some of whom have spoken out against the war — shouldn't be punished.

• One side: "Why is somebody who works in McDonald's in Russia losing their job ... and the tennis players are exceptions? ... It has to be even," former Ukrainian player Olga Savchuk said last week.
• The other side: "I feel very strongly that ... individual athletes should not be the ones that are being penalized by the decisions of an authoritarian leadership," WTA chief Steve Simon said last month.

The big picture: Wimbledon isn't alone. This week's Boston Marathon enacted the same ban, Russian and Belarusian athletes were barred from the Paralympics, and Russia was removed from World Cup qualifying.

What to watch: As of now, neither the French Open (next month) nor the U.S. Open (August) have indicated that they intend to ban players. But this announcement could change that.