Blackmail: Trump's ABC interview exposes the president as a national security threat -- here's how
President Donald Trump threatens his enemies from the Oval Office/CNN screen shot

President Donald Trump's acceptance of foreign intervention in the 2020 election poses a national security threat -- and exposes him to blackmail, according to a former federal prosecutor.

The president told ABC's George Stephanopoulos that he would accept offers of foreign campaign assistance, and might not report those overtures to the FBI, to defend his son Donald Trump Jr. -- who took a meeting in June 2016 with a "Russian government lawyer" peddling dirt on Hillary Clinton.

Barbara McQuade, former U.S. Attorney for the Eastern District of Michigan, explained in a Daily Beast column how that meeting compromised Trump and his son three years ago, and the president's invitation opened him up to new forms of corruption.

"Even sitting down and listening to an overture from a foreign government puts a candidate at risk of blackmail," McQuade wrote. "Many intelligence operations are based on offering someone something that they want – money, access, sex – and then using that enticement as a trap to coerce compliance with demands."

"The foreign adversary doesn’t even need to say out loud that it will expose the person’s betrayal to his country," she added. "The mere knowledge that the foreign government could expose a person’s unpatriotic acts may be sufficient leverage to induce someone to act in the best interests of the adversary and contrary to the best interests of his own country. The meeting alone compromises the candidate."

Trump's efforts to shield his son from consequences for that possibly illegal meeting further compromised him and exposed him to obstruction of justice allegations.

"Trump compounded the harm of the meeting with Russians by editing a press statement about the incident to omit any reference to the purpose of the meeting: to share information about Clinton," McQuade wrote. "This act further compromised him with Russia because it created an additional opportunity for them to leverage against him his lie to the American people."

"Trump’s comments that he would listen, and report to the FBI only if something was wrong, is wrong as a matter of good counterintelligence practice, and profoundly wrong as a matter of patriotism," she added.