The House impeachment inquiry has shown just how deeply America’s politics and foreign policy have been consumed by Russian misinformation, with accusations from Democrats and Republicans alike that the other side is embracing conspiracy theories, peddling fake news or spreading dangerous hoaxes in ways that advance Moscow’s interests. So it was striking on Thursday to see the woman who spent two-and-a-half years as Donald Trump’s top expert on Russia bluntly tell the House impeachment investigators that she intended to lead them to the truth.