Pompeo and his special representative for Iran, Brian Hook, have indicated that the administration’s goal in squeezing Iran is renewed negotiations with Iranian regime, according to two sources familiar with their thinking — something Trump has expressed a desire to do. But Bolton is a deep skeptic of the value of negotiating with adversaries who, before joining the White House, called publicly for regime change in Tehran.

While Pompeo has worked to carry out the president’s foreign policy directives, Bolton has done more to try to shape them — at times contradicting the president, as when he walked back Trump’s call for a rapid U.S. troop withdrawal from Syria…

Though Bolton and Pompeo largely have the same hawkish instincts, when disagreements have arisen, Bolton has made clear why he has a reputation as bare-knuckled bureaucratic infighter. He has placed the interagency national security process in a tight grip, aggressively shaping policy rather than acting as an impartial arbiter as many of his predecessors have done.