President-elect Donald Trump named retired Lt. Gen. Michael Flynn his national security adviser on Nov. 18, but Flynn has a history of making incendiary and Islamophobic statements that have drawn criticism from his military peers. (Peter Stevenson/The Washington Post)

President-elect Donald Trump’s pick for national security adviser, among the most important jobs in the still-forming Trump administration, has said some pretty incendiary things on the Internet.

Before being tapped to advise Trump on national security issues, retired Lt. Gen. Michael T. Flynn was an intelligence officer and head of the Defense Intelligence Agency under President Obama until he was removed from his command in 2014 over his leadership style. Flynn went on to criticize some of his superiors, including Obama, regarding their stances on Islamist extremism. He also traveled to Russia on a trip paid for by state-run media and met with Russian President Vladimir Putin. Flynn said that he was using the trip to advance U.S. interests.

Before joining the Trump campaign and drawing the ire of his colleagues for using his rank to support a political campaign that would often disparage the very establishment he had just departed, Flynn was well-regarded by his colleagues.

In his book “My Share of the Task,” retired Gen. Stanley McChrystal wrote that Flynn was “pure energy” and had an “uncanny ability” to digest information, “marshal his people, resources and energy to make it happen.”

Apart from his military career and political ascension, Flynn also has a digital legacy that is problematic. Below are some of his tweets over the course of the Trump campaign. Ryan Lizza, a writer with the New Yorker, also put a number of Flynn’s tweets on his feed Thursday night.

Read more:

‘Makeup helps women look more attractive’: This employee dress memo went around Lt. Gen. Michael Flynn’s DIA

He was one of the most respected intel officers of his generation. Now he’s leading ‘Lock her up’ chants.

Trump faces growing tension with key Republicans over national security issues