The trial of President Donald Trump’s onetime campaign chairman will open this week with tales of lavish spending, secret shell companies and millions of dollars of Ukrainian money flowing through offshore bank accounts and into the political consultant’s pocket. What’s likely to be missing: answers about whether the Trump campaign coordinated with the Kremlin during the 2016 presidential election, or really any mention of Russia at all. Paul Manafort’s financial crimes trial, the first arising from special counsel Robert Mueller’s investigation, will center on his Ukrainian consulting work and only briefly touch on his involvement with the president’s campaign. But...