Washington DC - Fox News anchor Pete Hegseth is facing more scrutiny about his past rhetoric as President-elect Donald Trump seeks to add him to his cabinet.

The five books Hegseth has published have been receiving heightened attention after Trump nominated him to be Secretary of Defense earlier this month.

His 2020 book American Crusade has been under significant fire, as recent reviews noted Hegseth sharing strong anti-Muslim rhetoric in the text.

According to The Guardian, the book argues that Islam is "a natural, historic enemy of the West" and claims that American liberals and Islamic fundamentalists are the same, as they both want to "subvert the US."

Donald Trump Trudeau opens up about call with Trump after shock tariff announcement

"By the eleventh century, Christianity in the Mediterranean region, including the holy sites in Jerusalem, was so besieged by Islam that Christians had a stark choice: to wage defensive war or continue to allow Islam's expansion and face existential war at home in Europe," Hegseth wrote in a chapter titled Make the Crusade Great Again.

"The leftists of today would have argued for 'diplomacy,'" he added. "We know how that would have turned out."

Hegseth believes crusaders were "safeguarding modern values," to which Islam supposedly presents an inherent danger. He described Muslim immigration to Europe as an "invasion" in tune with the white nationalist Great Replacement Theory.

He went on to argue that "hard-core leftism" presented by politicians like Senator Bernie Sanders "provides the best gateway for their Islamism."

Hegseth's rhetoric has many critics concerned due to the fact that if his appointment is approved by the Senate, Hegseth will lead the US military during a time when tensions in the Middle East are fraught.

He has also gained attention for his collection of tattoos, which include a large Jerusalem cross on his chest and "Deus Vult" on his arm – both of which reference the crusades and are common with extremist groups.

Hegseth and other MAGA allies have made it clear that the Trump administration will support Israel in whatever actions they deem appropriate in Gaza, where Israel's assault has already been classified as genocide by numerous human rights groups.