A former U.S. attorney spelled out how special counsel Jack Smith is forcing Donald Trump s hand and making him put his money where his mouth is with his latest move in the former presidents election interference case.

Smith this week asked U.S. District Court Judge Tanya Chutkan to order Trump to provide formal pre-trial notice of any intent to rely on advice of counsel as a defense, Barbara McQuade wrote in an essay for MSNBC published Thursday.

Trump has so far been able to have it both ways by protecting testimony and documents from disclosure as privileged, while also claiming that his conduct was lawful because he simply relied on what his lawyers told him, wrote McQuade, who was the U.S. attorney for the Eastern District of Michigan from 2010 to 2017 and is now a law professor at the University of Michigan and analyst for MSNBC .

Trump will now have to decide whether he wants to rely on that defense at trial and, therefore, disclose the communications between himself and his lawyers, including Rudy Giuliani, which may open him up to further scrutiny, she said.

Regardless of whether Smiths motion succeeds, at some point, Trump will have to decide whether asserting what may be a flimsy defense is worth sharing his trove of secrets, added McQuade.

Read the full essay here.