Protestors carry flags and a banner with the slogan “people’s impeachment” during a rally Sunday in downtown Kiev, Ukraine. (Sergey Dolzhenko/EPA-EFE/REX)

Maxim Eristavi is a nonresident research fellow with the Atlantic Council and co-founder of Hromadske International, an independent news outlet, based in Kiev.

Ukraine’s complex political intrigues can be hard to figure out. But this week we’ve arrived at a rare moment of clarity.

The most important domestic issue in our country is corruption. And for the first time in our modern history, we have the people and the institutions in place to fight it.

But at the very moment when anti-corruption officials have really started to tackle the problem, Ukrainian President Petro Poroshenko is moving to undermine them. His followers in parliament have dismissed the head of a crucial anti-corruption committee, and now they’re preparing to neutralize the National Anti-Corruption Bureau of Ukraine (NABU), its only independent anti-graft body, which has made a name for itself with aggressive prosecutions of high-ranking politicians.

And it’s not just happening in parliament. Last month, the Ukrainian intelligence agency and the general prosecutor’s office — both of which take their orders directly from the president — cracked down on NABU’s undercover investigations in Kiev. They also staged raids on the homes of 12 NABU employees and their relatives. This is the biggest blow to the operations of the agency since it was launched two years ago; several of its investigations have collapsed. Some of the anti-corruption fighters refer to what happened as “planned sabotage.”

The Ukrainian Security Service and the prosecutor’s office, with their almost unlimited powers and the combined forces of 45,000 employees, are on a crusade against the country’s tiny anti-corruption agency of fewer than 700 people. Imagine if the CIA and the U.S. attorney general conspired to attack a corruption unit within the FBI.

Activists in Kiev say that we’re approaching a tipping point. If the anti-corruption bureau is abolished or emasculated, it will sound the death knell for transparent democracy in Ukraine.

Western governments have channeled hundreds of millions in taxpayer money into Ukraine’s anti-corruption reforms. The time to protect that investment has come. The United States and the European Union should be telling Poroshenko and his friends that they must hold the line on corruption.

Such a message will be even more important given Poroshenko’s recent push to consolidate his power in next year’s national election. The president and his supporters have been squeezing the media and cracking down on their critics — all to a resounding lack of international outcry. Many in Kiev view the attacks on anti-corruption bodies as a gift from the president to his businessmen friends, who will support his reelection bid if they know he’ll protect them from prosecution.

Poroshenko clearly believes that his supporters in Washington and Brussels will back him no matter what, given the continuing war by Russian-supported forces in eastern Ukraine. The West sees the Ukrainian president as a bulwark against Russian designs in Eastern Europe — and it has given him plenty of reason to think so. Whenever I’ve asked Western diplomats why they’re so reluctant to pressure our government, I almost always hear the same answer: “The Russians will exploit any criticism to destabilize Ukraine.” In his recent address at the United Nations, Poroshenko mentioned Russia more than two dozen times. Corruption? Once.

In this respect, Poroshenko is starkly at odds with his own people. Independent polls show that Ukrainians regard corruption as one of their top worries — even more so than the war. Of course, we are worried about Russia’s efforts to destroy our country. Of course, Putin invaded our country. But Putin isn’t the one stealing state funds. Putin isn’t the one leaving holes in our roads. Putin isn’t the one helping our crooked bureaucrats to avoid jail. Putin isn’t forcing our elites to evade paying their taxes.

The government’s ham-handed attempt to arrest former Odessa governor Mikheil Saakashvili this week is the latest example of how far Poroshenko is willing to go to silence his opponents. At the same time, he is also trying to distract Ukrainian public and foreign allies from his attack on the anti-corruption bureau that was happening at the same time.

Our foreign allies can help Ukraine to end the rot. But they can’t do this unless they stop accepting the narratives pushed from government offices and start defending their own investments in Ukrainian progress. Otherwise those millions they’ve spent to help us will be stolen, and our sleaziest practices will migrate to the West — just as they did in the case of Paul Manafort, who assisted the most corrupt Ukrainian president in recent memory before he went to work for Donald Trump.

Where should Ukraine’s friends start? First, they should restore and guarantee the anti-corruption bureau’s independence by giving the EU anti-corruption mission in Ukraine the powers to act as a mediator and auditor. They should demand the launch of new anti-corruption courts no later than next year, so that anti-corruption cases can finally be tried outside the largely unreformed justice system.

Next, Ukraine’s allies must show that they know how to use not only carrots, but also sticks. They should warn the government in Kiev that the recently launched visa-free regime with the EU can be suspended if any efforts are made to further undermine NABU.

Ukraine’s anti-corruption reforms have proven a remarkable success — which is precisely why the leadership is so keen to dismantle them. Now is the time for reformers and their allies in the West to come to their defense.