The U.S. Secretary of Defense and former Marine Corps general James Mattis announced his resignation this past Thursday, following President Trump’s decision to withdraw all remaining troops from Syria. In a letter of resignation released by the Pentagon, Mattis signaled his dissatisfaction with the decision. Additionally, the Secretary outlined his belief that the United States must stand with its allies against “malign actors and strategic competitors,” specifically mentioning Russia and China. This comment appears to be directed at the President, who has spoken positively of Russian President Vladimir Putin and Chinese President Xi Jinping during his tenure. In closing, Mattis wrote that the President deserved a Secretary of Defense whose views were more in line with his own, giving February 28, 2019 as his departure date.

Sec. Mattis’ decision to depart comes on the heels of a similar announcement by Chief of Staff John Kelly, who intends to leave the White House by the end of the year. Kelly and Mattis served together in the Marine Corps, working hand-in-hand during the 2003 invasion of Iraq. Both men have tried to moderate some of the President’s more radical impulses while in office. In fact, the Associated Press reported that Kelly and Mattis agreed not to leave the country at the same time, lest the President make an impulsive decision. Now that Mattis and Kelly are departing, it’s unclear as of yet if there is anyone left in the administration to act as a check on the President.

The White House appears to be in turmoil. Other dismissals or resignations have come in recent weeks, including the departures of Attorney-General Jeff Sessions, Interior Secretary Ryan Zinke, and Ambassador to the United Nations Nikki Haley. Special Counsel Robert Mueller is close to releasing his final report on Russian interference in the 2016 election, which may prove calamitous for the President and his closest advisors. The President was forced to close his personal charity, the Trump Foundation, after allegations that donations were used towards personal expenses. All this comes as the the federal government careens towards a shutdown over the border wall after the President reneged on his agreement to fund the government through the beginning of February.