Trump’s search for a national security adviser sums up his biggest challenges so far

President Donald Trump’s next national security adviser will serve as his eyes and ears to crises that pop up all over the globe – and be thrust into the center of the White House’s biggest firestorms too. Amid the fallout over the firing of the first person to hold the post, Michael Flynn, the president has escalated his war with the media, questions have mounted about Trump associates’ ties to Russia, and his top pick to replace Flynn backed away, making it known he was concerned about how much autonomy he would have.