Guy Snodgrass is predicted to be the anonymous author of The New York Times op-ed last year and recent book 'A Warning'  

He served as former Defense Secretary Jim Mattis's speechwriter

Snodgrass posted the article guessing he was the writer to his Twitter with the caption: 'The swirl continues...' 

He did not deny writing the op-ed and book

'No comment at this time,' he responded when pressed by a Mother Jones reporter on whether he's the anonymous author 

Snodgrass wrote 'Holding the Line: Inside Trump's Pentagon with Secretary Mattis', which he published along with his name on it at the end of October

He also is a regular contributor for a handful of news outlets