4 things Trump should remember as he's picking his next national security adviser

After a rocky tenure, John Bolton is out as President Donald Trump's national security adviser.

Trump has made plain his feelings on some big foreign-policy issues, and those are areas he should keep in mind as he picks his next national security adviser, writes Defense Priorities fellow Gil Barndollar.

John Bolton has left the building. The famously mustachioed Washington insider stepped down as national security adviser yesterday, leaving behind a two-sentence letter and a silly argument over whether he resigned or was fired.

President Trump had been at loggerheads with Bolton for months: repeatedly contradicting him, joking to friends about Bolton's bellicosity, and literally exiling his national security adviser to Mongolia. Bolton's vehement opposition to canceled negotiations with the Taliban at Camp David was the final straw.

President Trump has said he will appoint a new national security adviser by next week. As he talks to staff and confidantes and considers his options, the president should think long and hard about his key national security priorities.

Based on his many statements as a candidate and as president, there are four major foreign policy goals that should drive Trump's selection of a philosophically aligned national security adviser.