Former Defense Secretary James Mattis was elected to the board of directors for aerospace and defense company General Dynamics on Wednesday. 

“Jim is a thoughtful, deliberate and principled leader with a proven track record of selfless service to our nation,” Phebe Novakovic, General Dynamics’s chairwoman and chief executive officer, said in a statement. “We are honored to have him on our board.” 

Mattis previously served on the General Dynamics board of directors from August 2013 to January 2017 before becoming President Trump’s Defense secretary. Mattis’s two-year stint at the Pentagon was a tumultuous stretch in which he often split from the commander in chief on high-profile issues.{mosads}

Mattis reportedly said the president had the understanding of “a fifth- or sixth-grader” when it comes to the Korean Peninsula, according to Washington Post journalist Bob Woodward’s book “Fear: Trump in the White House.”

He resigned in December in disagreement over Trump’s decision to withdraw troops from Syria, his frequent bashing of allies in NATO and his praise for rivals like China and Russia.

“My views on treating allies with respect and also being clear-eyed about both malign actors and strategic competitors are strongly held and informed by over four decades of immersion in these issues,” Mattis wrote in his resignation letter.

“We must do everything possible to advance an international order that is most conducive to our security, prosperity and values, and we are strengthened in this effort by the solidarity of our alliances.”

Mattis is currently the Davies Family distinguished fellow at the Hoover Institution at Stanford University.

General Dynamics, headquartered in Falls Church, Va., says it offers a “broad portfolio of products and services in business aviation; combat vehicles, weapons systems and munitions; IT services; C4ISR solutions; and shipbuilding and ship repair.” It employs more than 100,000 workers worldwide.