(Reuters) - U.S. Defense Secretary Jim Mattis will quit in February after falling out with Donald Trump over the president’s foreign policies, including the surprise decision this week to pull troops out of Syria and plan a drawdown in Afghanistan.

FILE PHOTO: Defense Secretary James Mattis listens as President Donald Trump speaks to the news media while gathering for a briefing from his senior military leaders in the Cabinet Room at the White House in Washington, October 23, 2018. REUTERS/Leah Millis

Mattis, a retired Marine general who embraced NATO and America’s traditional alliances, laid bare his division with the president in a resignation letter that underscored what have been a litany of differences with Trump, albeit without public attacks.

The following is a list of those differences:

TORTURE

- In a Republican presidential debate in 2016, Trump indicated he might order the U.S. military to break the law on interrogation tactics, including using waterboarding.

- Mattis said he opposed the use of torture and was subsequently able to convince Trump that the United States should not employ those tactics.

- “(Mattis) said: ‘I’ve always found, give me a pack of cigarettes and a couple of beers and I do better with that than I do with torture.’ And I was very impressed by that answer,” Trump said in November of that year.

NATO

- Trump has been a frequent critic of NATO, which he has described as “obsolete,” as he pushed to get member countries to live up to an agreement to spend at least 2 percent of their gross domestic product on defense by 2024.

- In a May 2017 a visit to NATO headquarters in Brussels, Trump pointedly did not mention U.S. support for the critical portion of the NATO charter under which allies should come to each other’s assistance if attacked. He used his speech there to demand that members pay more for the alliance’s defense.

- Eventually Trump backed the NATO charter’s demand that all members be prepared to defend each other.

- Mattis has been a strong proponent of alliances, in particular NATO, and has talked about the importance of American global influence.

- In his resignation letter, he mentioned NATO as an alliance that is needed and said he would stay in his job until the end of February in part to be able to attend a NATO meeting.

IRAN

- Trump has long railed against a 2015 deal between world powers and Iran under which Tehran accepted curbs on its nuclear program in return for nations lifting economic sanctions.

- Trump upset European allies by withdrawing the United States from the deal in May 2018.

- In October 2017, Mattis had said the United States should consider staying in the Iran agreement unless it was proven that Tehran was not abiding by it or that it was not in the U.S. national interest to do so.

SYRIA/AFGHANISTAN

- Mattis’ abrupt announcement that he was quitting followed disagreement with Trump over his decision to withdraw all U.S. troops from Syria. The president’s move to start planning a drawdown in Afghanistan was also blow to Mattis, who advocated for a strong U.S. military presence to bolster diplomatic peace efforts.

- Mattis had advised against the Syria withdrawal. One official said it was a contributing factor to his resignation.

COMMENTS

- Mattis’ future became a particular focus of media speculation after the September 2018 release of a book by Watergate reporter Bob Woodward that portrayed Mattis privately disparaging Trump, comparing the president to a schoolchild. Mattis strongly denied making any such remarks.

- The next month, Trump said of Mattis, “I think he’s sort of a Democrat, if you want to know the truth.”

SPACE FORCE

- In June 2018, Trump said he was ordering the creation of a sixth branch of the military to focus on space.

- While eventually saying a space force was necessary to protect American satellites, Mattis had written to lawmakers in 2017 saying that he opposed the idea because it added an additional organization and more bureaucracy.

NORTH KOREA

- The White House was reported in February 2018 to have become increasingly frustrated at the Pentagon’s reluctance to produce plans for a military strike against North Korea. Previously, Trump and some of his advisers had discussed delivering Pyongyang a “bloody nose” pre-emptive attack.