Kenneth Roth is executive director of Human Rights Watch.

Russian President Vladimir Putin speaks at the 2018 soccer World Cup draw at the Kremlin in Moscow last December. (Ivan Sekretarev/AP)

As the World Cup begins next week in Russia, 2.3 million civilians in Syria’s Idlib province are facing an endgame of their own. The two events are linked because the Russian government could play a central role in avoiding mass atrocities in Syria but so far has played the role of accomplice.

World leaders should avoid the spectacle of celebrating the World Cup’s opening alongside the Kremlin leadership unless it stops the slaughter of civilians in Syria. The opening ceremony will be marked with pomp and fireworks on June 14.

The Syrian conflict has been characterized by the government’s deliberate targeting of civilians and civilian institutions such as hospitals and schools in areas controlled by anti-government forces, and its indiscriminate bombing of civilian neighborhoods in those areas, in flagrant violation of the laws governing armed conflict. This war-crime strategy is a major reason that the conflict has killed almost half a million people and has displaced some 60 percent of Syria’s prewar population, roughly half within the country and half as refugees.

Rather than oppose this war on civilians, the Russian government has joined it. Russian bombers provide indispensable military support and regularly fight alongside Syrian aircraft — a key reason that President Bashar al-Assad, whose battlefield position had been tenuous, now looks increasingly likely to prevail. For example, Russia played a central part in the Syrian government’s indiscriminate bombing of the civilian populations of Eastern Aleppo and Eastern Ghouta the two most populous enclaves held by anti-government forces — while pro-government forces starved them through crippling sieges. The ensuing slaughter was sufficient to force both enclaves to fall.

Similarly, Russian arms companies are the biggest weapons suppliers to the Syrian government. Russian diplomats provide overt political support, blocking efforts to refer Syria to the International Criminal Court and vetoing an investigation that could have identified the perpetrators behind the Syrian government’s apparent use of sarin and chlorine as chemical weapons. And Russian state-affiliated media have been at the forefront of whitewashing these atrocities.

Today, the biggest remaining region held by anti-government forces is Idlib, where the civilian population is divided roughly evenly between local residents and those who have been displaced from elsewhere in the country. Idlib has been the dumping ground for civilians and fighters who have been forced out of other areas held by anti-government forces, but there is now nowhere else inside Syria for them to go as they are squeezed between Syrian forces on the ground, Turkish forces along the northern border, and Syrian and Russian bombers firing from above.

For 3.5 million Syrian refugees, Turkey has been a haven, but it has since closed its border to new arrivals. Turkish security forces have been firing at asylum-seekers trying to cross the border irregularly and have summarily deported thousands from border areas. But Syrian refugees are still reaching European Union territory, despite the E.U.-Turkey migration deal designed to restrict that route, and those numbers could increase, particularly if there is a big influx from Idlib.

A far preferable solution to potentially forcing another 2 million Syrians from their country would be for the Russian government to force an end to the war-crime strategy of targeting civilians. That does not mean giving a break to the armed groups that now control Idlib, many of which have their own record of atrocities. But it means fighting them in accordance with international humanitarian law, targeting only combatants and no longer targeting, or firing indiscriminately upon, the civilians living nearby or on protected institutions such as hospitals and schools.

Russia clearly has the leverage to secure an end to these atrocities. Its bombers could refuse to take part in them or to back the Syrian military while it commits them. Its arms companies could stop supplying weapons while the atrocities continue. Its diplomats could stop shielding Syrian officials from international prosecution of their war crimes and international investigations that would expose them as users of chemical weapons. The key is getting Russia to use that leverage.

The World Cup provides an opportunity. No one objects to the players taking the field and the public enjoying the competition, or to officials going to Russia to cheer on their teams. But opening ceremonies are almost always a pageant to glorify the leadership of the host country. Unless there are concrete indications of change, government representatives should announce that they will not join Kremlin leaders in this spectacle, as long as those same Kremlin leaders underwrite mass atrocities in Syria. The Russian-Syrian war-crime strategy is simply too dire and deadly to paper over with a change-the-subject champagne toast.

Read more:

Anne Applebaum: Russia is lying about Syria, but Trump has no credibility to counter it

George F. Will: Firing missiles into Syria is cathartic, but catharsis isn’t foreign policy