“My team and I have no desire to be a cover for open corruption or puppets for those who want to establish control over state funds in the old fashion,” Abromavicius wrote. “These people have names. And one of these names I am going to mention. It is Igor Kononenko. As a representative of the political force that nominated me a minister, he has done a great deal recently to block the work of my team and me,” he concluded.

Abromavicius further explained that Kononenko tried to get Parliament to fire him; pushed his people for positions at state-owned enterprises; and arranged for a loyalist to be appointed deputy minister in charge of Naftogaz.

In the short run, there is no question that the loss of Abromavicius is bad news for those hoping to change Ukraine. Abromavicius is a strong reformer, and carried out changes in state procurement reform, deregulation and by improving corporate governance in state enterprises. Along with Finance Minister Natalie Jaresko, he was considered a key economic reformer, someone whose presence provided comfort to major international donors and investors.

Although the downside to Abromavicius’ departure is substantial, two good things may yet come out of it. First, it’s an opportunity for the new National Anti-Corruption Bureau – considered by reformers to be the “point of the spear” in the anti-graft war – to shine.

The new agency seems eager to make use of the opportunity, registering a criminal case against Ihor Konenenko – the first deputy head of parliament’s President Petro Poroshenko Bloc – immediately after Abromavicius released his resignation letter.

Former Security Service of Ukraine Chief Valentyn Nalayvychenko already presented evidence of Konenenko’s corruption in an open parliamentary hearing in October, and there is surely much with which to work if the anti-corruption bureau wants to build a serious case against Konenenko.

Whatever the outcome, the bureau’s future credibility now depends on two things:

First, the agency’s willingness and ability to truly investigate Konenenko himself, as well as any leads that spin off a Konenenko investigation.

And second, whether or not key figures – including Poroshenko himself – provide the burea with the full support it needs. In sum, the National Anti-Corruption Bureau faces trial by fire, and if it properly handles the political heat it could emerge as a powerful new tool in the fight against graft.

The second silver lining from Abromavicius’ departure is that it raises the corruption issue to perhaps its highest level of visibility since Poroshenko took power. In response to events, ten Western ambassadors to Ukraine released a public letter, noting they were “deeply disappointed” by Abromavicius’ decision to resign, and praising him for his accomplishments. The letter concluded with a stinging rebuke to Ukraine’s feuding politicians: “It is important that Ukraine’s leaders set aside their parochial differences, put the vested interests that have hindered the country’s progress for decades squarely in the past, and press forward on vital reforms.”

While the letters released by Abromavicius and the Western ambassadors are an embarrassment for Poroshenko, they may help Ukrainian reformers. With Ukraine due another $4 billion in aid this month from the International Monetary Fund, European Union and the United States, Kyiv remains dependent on Western support for financial survival. Western leaders’ confidence in Poroshenko’s administration is already sinking, and he will certainly now face unprecedented pressure from the West to finally get serious about confronting graft.

To be clear, this type of intense pressure is exactly what Ukrainian reformers want.

Ukraine’s Anti-Corruption Action Center recently tweeted: “We beg [the] West to help us fight government impunity,” while another activist said civil society appreciated the pressure the United States puts on the government to fight corruption and wants all European Union countries to take a similarly strong line.

Ideally, Western countries and international donors will now tell Poroshenko to either get onboard the anti-corruption train – starting by removing the anti-reform Prosecutor General Viktor Shokin – or else face a cut-off in all financial aid.

Yegor Sobolev, who heads the anti-corruption committee in parliament, goes a step further. Sobolev sees two possible courses of action for Poroshenko after the Abromavicius bombshell. One is to shuffle the chairs within his government, but make no substantive changes – something Sobolev believes makes further disappointment and radicalization in society inevitable.

Rather than risk duplicating Yanukovych’s fate though, Sobolev hopes Poroshenko will instead elevate a genuine reformer such as Odesa Oblast Governor Mikheil Saakashvili to prime minister with a mandate to reinvigorate reforms. If this occurs, Abromavicius’ resignation will turn out to have a very wide silver lining after all.

Josh Cohen is a former U.S. State Department project officer involved in managing economic reform projects in the former Soviet Union. He works for an information technology company and contributes to a number of media outlets. Follow him on Twitter: @jkc_in_dc.