In 2012, as Greg Craig considered taking on a project for the Russia-aligned government of Ukraine, a colleague in London raised concerns that the work would create a “no-win situation” for their law firm, Skadden, Arps, Slate, Meagher & Flom.

Craig, a prominent Washington lawyer who’d recently served as President Barack Obama’s first White House counsel, had been asked to prepare an independent report for Ukraine on the widely criticized prosecution of the country’s former prime minister, Yulia Tymoshenko. Before signing on, Craig consulted Bruce Buck, then a senior partner in the firm’s London office, who asked whether he’d considered the “implications” of the Skadden team concluding that Tymoshenko did not receive a fair trial.