President Donald Trump's decision to release House Intelligence Committee Chairman Devin Nunes's memo alleging wrongdoing at the Justice Department, combined with his ill-advised intervention with the Justice Department over the issue, represents the most unethical - and potentially illegal - action he has taken since he fired FBI Director James B. Comey. And like the Comey decision, it may now feature prominently in the obstruction of justice investigation dogging Trump's White House.

What makes the President's involvement so fundamentally inappropriate is the fact that the Nunes memo cannot be disentwined from the active, ongoing investigation into the President and his 2016 campaign.

The memo's accusations are drawn from a secret court application by the Justice Department for permission to surveil Trump campaign official Carter Page, as well as a subsequent renewal that was authorised by Deputy Attorney-General Rod J. Rosenstein. Because of this entanglement, the White House should have taken the traditional hands-off stance of previous administrations and left the Justice Department to handle the matter independently.

Instead, the president directed his chief of staff, John F. Kelly, to castigate Justice Department officials for sending Nunes a letter claiming the memo's public release could compromise the Russia investigation or jeopardise national security by revealing classified secrets.