How Mattis softened on Iran -- for now

But another factor is the change in presidents: Instead of working for a commander in chief he viewed as weak on Iran, he now works for one who at times appears to be picking a fight.

“He has to be very sensitive to where the president is,” said James Jeffrey, who was Obama’s ambassador to Iraq when Mattis headed Central Command. “With Obama he had a president who was very reticent to challenge Iran militarily … so he was forward-leaning, and that probably hurt his relationship with Obama.”

Now, Jeffrey said, Mattis is “dealing with a president who is both extremely aggressive on Iran and very volatile. So he has to be the cautioner, the balance of reason, the ‘look before you leap’ guy. You see him doing this with North Korea, and you see him doing it with Iran.”