[citation needed] He attended Middlebury College for his undergraduate degree in English, graduating cum laude, Phi Beta Kappa.

[1] In September 1998, Deitz left a partner position in private practice at the Washington, D.C. office of international law firm Perkins Coie to return to public service to head the Office of the General Counsel, or D2[2] at the National Security Agency, responsible for representing the agency in all legal matters.

[1][4] While at NSA the agency's legal burdens were heavily focused on the warrantless surveillance programs later exposed by Edward Snowden in 2013.

On Snowden's allegations that while at NSA officers "at any time can target anyone, any selector, anywhere,” or "wiretap anyone from you or your accountant to a federal judge to even the president if I had a personal email”, Deitz called the claim a “complete and utter” falsehood.

There are, from time to time, cases in which some analyst is [angry] at his ex-wife and looks at the wrong thing and he is caught and fired”[5] After the USA Freedom Act was signed into law by President Obama in 2014 as a compromise between civil libertarian demands and security hawk efforts to preserve certain spying tools, Deitz expressed skepticism that the legislation would offer much anything in the way of reform in either direction, saying "it’s being talked about like it’s the Declaration of Independence or something, these adjustments are marginal.”[6] Deitz left the NSA with Director Michael Hayden in September 2006 to follow his boss to the Central Intelligence Agency, where Hayden became Director, and Deitz served as Senior Counselor to the Director.

[8] Deitz's teaching at George Mason was the subject of criticism from Ken Silverstein of The Intercept, who argued that Deitz was unfit to teach courses on ethical challenges in public policy on accord of his legal work in defense of NSA warrantless surveillance programs and what Silverstein claimed was a politically motivated investigation Deitz conducted into former CIA Inspector General John Helgerson's review of the agency's extraordinary rendition, black sites, and enhanced interrogation practices at the behest of Director Michael Hayden.