Prince Harry and Meghan Markle
Prince Harry and Meghan Markle's marriage will be successful at her cost. Pictured: Prince Harry and Markle wave as they leave Windsor Castle after their wedding to attend an evening reception at Frogmore House, hosted by the Prince of Wales on May 19, 2018 in Windsor, England. Getty Images/Steve Parsons

Germaine Greer believes that the Duke and Duchess of Sussex's marriage will work. However, it would be at the expense of the new royal.

The Australian feminist author was recently asked about Prince Harry and Markle's marriage and whether or not she believes it will work. Greer notably took a deep breath and paused before hinting that the duchess may have to do the heavy lifting in their relationship.

"Yes, but it will be at somebody's cost," Greet told RT (via Express). "I think it will be at Meghan's."

According to the feminist advocate, Markle has to learn "deference." The former "Suits" actress should recognize the fact that in the Firm, she should recognize who comes before her.

"She has to learn deference. She has to learn who comes before whom," Greer continued. "She has to curtsey to other members of the Royal Family."

Aside from this, Greer also has a warning for Markle. "I think she should run for her life. I think she should grab Harry and get going," she added. "It would have been smart to marry in Toronto and send them a post-card saying 'we've done it and it's too late now.'"

As for Markle's safety now that she's an official royal, she will receive special security treatment. According to royal police expert Chris Jagger, the Duchess of Sussex has already been enjoying the privilege since she started dating Prince Harry.

"Since her relationship with Prince Harry went public, she has been under full protection," Jagger told Us Weekly. "To be forever in the public eye with very limited privacy isn't a life suited to all. But as I understand it, both Meghan and Harry spent a significant period of time discussing and exploring whether or not this was the sort of life she wanted. She is surrounded by wise advisers who will help her make the transition from her old life into her new one."

In related news, following Prince Harry and Markle's royal engagement, it was reported that the "Horrible Bosses" star taken steps to protect herself better. Markle reportedly sought the help of a professional martial arts trainer to learn the basics of self-defense. Specially trained officers also worked with her to teach her what to do during terrorist attacks.

"Meghan will be trained in many different [areas], including what public places she should avoid, what she should do if she was ever approached and attacked in public and how to release herself from a situation like that," a source told Entertainment Tonight.