President-elect Donald Trump will nominate retired Marine General James ‘Mad Dog’ Mattis to be the 26th secretary of defense, the Washington Post reported. He would also serve as a member of the National Security Council. If confirmed, he would replace the current secretary, Ash Carter, who was confirmed in February 2015. However, Congress must pass a waiver before that happens because federal law states that service members must wait seven years after retiring from active duty before they can hold senior civilian defense positions, including secretary of defense. Trump referred to Mattis as "a true General's General" after the two met on November 19. The Department of Defense was originally created as the War Department in 1789 to “plan, advise, and carry out the nation’s security policies…