Behind Bolton’s decision

Former national security adviser John Bolton shook up the Trump impeachment standoff recently with his announcement that, if subpoenaed, he is “prepared to testify” before a Senate trial. It’s still not clear, of course, when or even if a trial might occur, since House Speaker Nancy Pelosi is withholding the articles of impeachment. But if there is a trial, and if the Senate subpoenas Bolton, he w…