The approach, he said, sent Giuliani on a monthslong hunt for information from Ukraine that would be damaging to the enemies of his client. That effort culminated on Thursday with the release of a whistleblower’s complaint about those efforts, followed by a furious attempt to discredit the complaint.

“I’m the real whistleblower,” declared Giuliani, who claimed to possess more damaging information and insisted that he, too, should be entitled to whistleblower protections. “If I get killed now,” he warned, “You won’t get the rest of the story.”

The rest of the story goes back even further, to a long-running geopolitical saga and a bureaucratic turf war in Kiev. There, a group of Ukrainian prosecutors with grudges against Western-backed anti-corruption efforts found common cause with a network of Trump’s allies with a long history of digging up dirt on Democrats.

Over several months, that volatile combination set off a chain reaction that is now roiling both capitals. It threatens to bring about Trump’s impeachment and inflict collateral damage on the presidential campaign of Democratic front-runner Joe Biden.

Prologue

For years, Ukraine has found itself caught in a tug-of-war between the West, which wants it to embrace the rule of law, liberal democracy and a market economy, and Russia, which wants to reassert dominance over its former imperial possession.

In that contest, the toppling of Russia-aligned President Viktor Yanukovich in February 2014 was a blow to Moscow. It would also create problems for the ousted leader’s American consigliere, Paul Manafort, and for Mykola Zlochevsky, a natural gas baron who had served in his cabinet.

The following month, Moscow responded by annexing Ukraine’s Crimean Peninsula. Zlochevsky, meanwhile, found himself on the outs with the new regime and facing investigations at home and in the West. In April, he responded by putting Hunter Biden, whose father oversaw U.S. policy in Ukraine, on the board of his natural gas company, Burisma Holdings.

In September 2014, Ukraine’s new president, businessman Petro Poroshenko, came to Washington to appeal for help repelling Russian incursions into eastern Ukraine, which had escalated in August. He warned a joint session of Congress that “blankets [and] night vision goggles are also important. But one cannot win a war with blankets … and cannot keep the peace with blankets.”

In October, as it sought to ingratiate itself with the West, Ukraine established the National Anti-Corruption Bureau, or NABU, pledging to clean up its notoriously dirty political culture.

But while Ukraine’s new leaders were dependent on the West’s military support and eager for access to its rich economies, they did not all share the West’s enthusiasm for rooting out the country’s endemic corruption.