Amid all the strike talk floating around Chicago lately, same as four years ago, something’s noticeably absent this time around: Smack talk.

Chicago’s teachers still haven’t banged out a new contract with the Board of Education, but the rhetoric around the negotiations is much subdued compared to 2012, when the red-clad union made good on its threats to strike.

Mayor Rahm Emanuel hasn’t uttered anything nearly as inflammatory as the time he accused the teachers of getting paid while the kids got “the shaft.” The allies who pitched the mayor’s agenda last time are so far nowhere to be seen.

That’s despite the Chicago Teachers Union’s recent decision to take another vote in two weeks to shore up support for a strike that could begin in October.

Last time, Emanuel’s friends at Democrats for Education Reform, also known as DFER, which is backed by hedge funders, sponsored anti-strike rallies and ads that poked at the teachers.

Lewis flat-out called Emanuel a “bully” and a “liar” at a 2012 Labor Day rally, where she portrayed the contract fight as one over “the very soul of public education not only in Chicago but everywhere.”

By contrast, this year, Emanuel now is publicly backing the work of teachers, even demanding an apology from Gov. Bruce Rauner after the mayor’s one-time friend was quoted as calling half of them “virtually illiterate.”

DFER no longer has a chapter in Illinois. Its national press shop did not respond to messages seeking comment, nor did its former local head.

And Emanuel’s appointed CEO, Forrest Claypool, also speaks of generosity when discussing negotiations, and of rewarding teachers as much as possible for work he considers well-done.

“I’m not frustrated” about negotiations, Claypool said at a recent school annex unveiling. “Optimistic, I think,” interjected his education chief, Janice Jackson.

Asked last week what the mayor may have learned in 2012, CTU president Karen Lewis joked, “Not to mess with me. ‘Cause, don’t start none, won’t be none.”

Labor expert and University of Illinois at Urbana-Champaign Professor Robert Bruno has noted the relative quiet.

“From the CPS side, I imagine it really didn’t do them any good to provoke the teachers,” said Bruno, who’s about to publish a book about the strike of 2012. “Every time the mayor seemed to disparage teachers as he famously did on a couple of occasions . . . it just further inflamed the teachers.

“When he was perceived as leaning on groups like DFER and other . . . groups that had been antagonistic to teachers unions, the union capitalized on that and could characterize him as not just an administrator and mayor but as someone who was dangerous to the teachers,” he said.

Then, lots of parents supported the teachers when they walked out for seven days for the first time in a generation.

Bruno said the mayor and union also recognize the context in which they tussle over a contract. They will soon need more help from state legislators and a governor who has already suggested the broke CPS ought to declare bankruptcy.

Lewis also thinks that Emanuel needs to play nice because he’s politically weaker than when he first took office, thanks to the fallout from the fatal shooting of Laquan McDonald and other police-involved shootings caught on camera. So he can’t afford to have teachers walk picket lines for a second time under his watch, Lewis said.

“So I think he’s probably chilled out a lot, not because of anything we’ve done, but because the political climate is quite different,” Lewis said at CTU headquarters. “And he hasn’t been involved in any of the interesting parts of the presidential . . . his name isn’t mentioned for anything in Washington.”

She and Emanuel’s camp both said they’re no longer new to each other.

“It was one of those things where everyone had to feel themselves out,” Lewis said. “They’ve figured out that we’re going to continue moving, we’re going to continue organizing with communities and families, for what’s best for the kids and what’s best for us.”

Mayoral spokesman Adam Collins also said that the “big contentious issues are really behind us,” noting that a controversial way to evaluate teachers using standardized tests emerged in 2012 as did Emanuel’s longer school day.

This contract is more about typical labor issues: raises and pensions, he said. “I think it’s not if there’ll be a raise and if the pensions will be secure — it’s how much or how big, and we’re trying to help on that front.”

And of course the famously contentious personal relationship between the union chief and mayor — soured after Emanuel hurled the F word at her before taking office — also has mellowed, since Lewis was diagnosed in 2012 with a brain tumor that halted her planned run to challenge him for mayor.

“There is some level of regularity in which there’s communication,” Collins said. “And because there’s a different line of communication, while they might not agree on everything, they can disagree without being disagreeable.”