Final answer:
The provided references do not specify the frequency at which the DoD IG must report to Congress on IG allegations of reprisal. These reports are part of the process to ensure that IC employees can safely report concerns. Legislative actions and court decisions highlight the dynamics of government transparency and the protection of whistleblowers.
Step-by-step explanation:
The frequency at which the Department of Defense Inspector General (DoD IG) provides a report to Congress detailing the Services' Inspector General (IG) allegations of reprisal and restriction from communication with Congress is not explicitly stated in the provided references. These reports are a critical component of maintaining transparency and accountability within the Intelligence Community (IC) and ensuring that personnel can report urgent concerns without fear of reprisal.
As per the references, individuals within the IC have a protected avenue to report concerns to Congress, particularly relating to urgent matters that could affect national security, as prescribed in 50 U.S.C. § 3033(k)(5)(A). Where large-scale policy issues occur, such as the repealing of 'Don't Ask, Don't Tell' (DADT) or Defense of Marriage Act litigation, the role of Congress in overseeing and enforcing legislative changes becomes apparent through formal letters and reviews.
Additionally, historical decisons such as the Supreme Court’s refusal to hear journalist James Risen's appeal underscore the continuous evolution of government transparency and the protection of sources and whistleblowers.