Here’s another black eye for the Justice Department’s Obama-era leadership: The case against Gen. Michael Flynn is in full collapse.

Federal prosecutors just backed down from their demand that Flynn — President Trump’s first, short-lived national security adviser — serve jail time for lying to FBI investigators, telling a court Wednesday that probation would be a “reasonable” sentence.

In fact, Justice had long wanted leniency, since Flynn cooperated fully with special counsel Robert Mueller’s investigations. But last month it started seeking up to six months of confinement — mainly because he’s no longer taking responsibility for his crime.

“I am innocent,” he writes in a new filing, explaining that he pleaded guilty in 2017 to making false statements to the FBI because he felt helpless to fight the charges: He’d already had to sell his home to pay legal costs and was told his son could be indicted, too.

The “crime” came days after the inauguration, when FBI agents Peter Strzok and Joe Pientka questioned Flynn at the White House about his conversations with Russian Ambassador Sergey Kislyak.

Yet the FBI had already reviewed transcripts of the calls and found nothing illicit. The visit was a fishing expedition: The agents even skipped the customary heads-up to the president’s Office of Legal Counsel — aiming to avoid having a lawyer present for the talk.

Even so, Strzok and Pientka wound up finding “no indication” that Flynn had lied to them. But then FBI lawyer Lisa Page (Strzok’s mistress at the time) instructed them to alter their official writeup of the conversation to say otherwise. And that’s the entire basis of the charges against him.

This wasn’t even the only abuse of power here: Before the inauguration, National Security Adviser Susan Rice ensured that the fact of Flynn’s conversations with Kislyak would leak to the media. Then holdover Justice official Sally Yates talked up ridiculous charges that he’d violated the never-enforced, and plainly irrelevant, Logan Act.

That phony controversy forced him from office — leaving him a private citizen when the Justice Department came knocking.

We were never big Flynn fans: He was an idiot to take payment from the Kremlin-sponsored news service RT for a 2015 speech in Moscow where he wound up seated next to Vladimir Putin, and a fool to do lobbying work on behalf of Turkish despot Recep Tayyip Erdogan right up until he started work at the White House.

But that doesn’t excuse these ambushes by Justice Department professionals — behavior that makes it easier to understand the president’s distrust of the “deep state.”