United States President-elect Donald Trump has offered the position of National Security Adviser to Lt. General Michael Flynn, who has called Islam a "cancer" that he is "at war" with. 

Flynn formerly served as the director of the Defense Intelligence Agency under President Barack Obama, but they clashed significantly over the president's refusal to use the term "radical Islam." 

Obama has consistently refrained from using the term, arguing that it wrongly suggests that all Muslims are associated with terrorists and their ideology.

This didn't sit well with Flynn, and he has made it his mission to promote the term. He heavily criticized Hillary Clinton for following Obama's example throughout her campaign. 

But, Flynn's insistence on using this specific term is only the icing on the cake for a deep-seated revulsion towards the religion. 

Here's an overview of some of his most Islamophobic moments.

1. He called Islam "a cancer"

In August, Flynn spoke at a gathering in Texas for ACT! for America, a group headed by Brigitte Gabriel, and called Islam "a cancer." 

He continued to say that Islam is “a political ideology” that “definitely hides behind being a religion,” while playing up rumors that Sharia law is being secretly implemented in the U.S.

2. He has said that fearing Muslims is "rational"

Posting to Twitter in Frebruary, Flynn shared a YouTube video that brazenly misrepresents Islam. The video's caption says: "please keep in mind that term Islamophobia is an OXYMORON since having a Phobia means having an IRRATIONAL FEAR."

With the link to the video, Flynn wrote: "Fear of Muslims is RATIONAL."

3. He said Muslim leaders should declare Islamic ideology "sick"

Following the July attack in Nice, in which a Tunisian resident of France drove a cargo truck through a crowded promenade killing 86 people, Flynn made an angry demand of Arab and Persian leaders. 

He said they should "declare their Islamic ideology sick."

Although the attacks were claimed by ISIS, one-third of the victims were Muslims. Interviews with family members and associates of the attacker also suggested that the man wasn't religious, and in fact he had a history of substance abuse and criminal activity.

4. He Tweeted an article that equates ISIS with Islam

The article argued that the terrorist group ISIS is "very Islamic" and should be seen as a religious group. This runs contrary to declarations by more moderate leaders that ISIS is an extreme perversion of the religion. 

The article says: "But the religion preached by [ISIS's] most ardent followers derives from coherent and even learned interpretations of Islam."

5. He said he has been "at war" with Islam for a decade

In a January interview with Al Jazeera, Flynn said:  "I've been at war with Islam, or a, or a component of Islam, for the last decade."