Today’s quiz: What do Vladimir Putin’s aggression and ObamaCare’s troubles have in common? OK, that was too easy.

It is impossible to dismiss as mere coincidence the Russian Bear’s invasion of Ukraine and the continuing mayhem of the Affordable Care Act. In their own ways, each reflects the full flowering of the policies of Barack Obama.

His chickens are coming home to roost, and what a mess they are making.

Obama’s sixth year in the White House is shaping up as his worst, and that’s saying something. He’s been in the Oval Office so long that it is obscene to blame his problems on George W. Bush, the weather or racism. Obama owns the world he made, or more accurately, the world he tried to remake.

Nothing important has worked as promised, and there is every reason to believe the worst is yet to come. The president’s casual remark the other day that he worries about “a nuclear weapon ­going off in Manhattan” inadvertently reflected the fear millions of Americans have about his leadership. Not necessarily about a bomb, but about where he is taking the country.

We are racing downhill and he is stepping on the gas. Will he stop before the nation crashes?

Ideologues love to dream, and some do it eloquently. Robert Kennedy famously said: “There are those who look at things the way they are, and ask why . . . I dream of things that never were, and ask why not?”

Mario Cuomo, no slouch at dreaming, nonetheless offered a caveat, saying, “You campaign in poetry, you govern in prose.”

Obama hasn’t figured out the difference. Even more alarming, he shows no signs of trying to learn. In the ways of the world, he remains a know-it-all rookie.

The view from his faculty lounge has no space for reality. Anything that doesn’t fit the grand plan is dismissed as illegitimate. So while global hot spots multiply and the world grows dangerously unstable, the president still plans to slash the military.

His trip abroad last week further secured his reputation for historic ineptitude. It wasn’t that the trip was a disaster — it never rose to that level. His presence and his promises simply made no difference.

He failed to move the European Union toward a firmer stance on Russia, created bizarre headlines by differing with the Vatican over what he and the pope discussed, and got not-so-veiled threats from the Saudis about Syria and Iran.

He could have stayed home and not done worse.

No president can win ’em all, but Obama’s foreign-policy record is unblemished by success. From east to west and north to south, America’s standing and influence have declined universally.

It is impossible for a US president to be irrelevant, but Obama is testing the proposition.

The frequent reports that Putin laughs when Obama warns of consequences can’t be far from the truth. Otherwise, Putin would be cautious instead of carving up neighbors and massing his military. It was also noteworthy that, after their Friday phone talk, ­Putin copied the Vatican and put out his own version of the discussion. Two can play the spin game, he seemed to be saying.

ObamaCare is the domestic expression of the president’s ineptitude. The law that was supposed to fix health care has become a problem for millions, and now enjoys mere 26 percent approval, a poll finds. It is proving so unworkable that the White House has given up defending it as written and instead simply changes key provisions when they prove impossible to implement or politically inconvenient.

Change No. 38 came when officials extended the March 31 deadline for signing up. Never mind that those same officials said recently there would be no extension, and that the law wouldn’t allow it.

Presto — the limits on his power are moot because the president says so. Meanwhile, aides claim they don’t know how many of the 6 million who enrolled actually paid for insurance.

A Caesar at home and a Chamberlain abroad, Obama manages to simultaneously provoke fury and ridicule. He bullies critics here while shrinking from adversaries there.

He divides the country and unites the world against us, ­diminishing the nation in both ways. His reign of error can’t end soon enough, nor can it end well.

Bronze meddle by gov’t tan foes

A chain of tanning salons has learned an important lesson: Only the government can legally lie.

Hollywood Tans, which has seven franchises in New York and scores around the nation, promises to stop promoting certain health benefits of tanning in a deal with New York’s attorney general.

I guess that means the company can’t claim that “if you like your tan, you can keep your tan.”

A backpedalin’ biz

Color me confused. The Wall Street Journal reports that business experts say the big problem with Citi Bike is that the system is “underpriced and underused.”

In theory, then, raising prices will yield more customers. Really — that’s how business works?

Water under Chris’ bridge

Outrage! Scandal! Waste! You have to marvel at the absolute certainty of those who are denouncing a report that found Gov. Chris Christie knew nothing about the Bridgegate lane closings.

It is true Christie’s office hired the lawyers who did the report, but does that make it less credible than the probes being conducted by Jersey Democrats who repeatedly accuse him of lying? And the report is no more biased than The New York Times’ breathless coverage, which is as naked as the ladies in Bada Bing!

The Gray Lady outdid itself in Saturday’s paper with a snarling package that included a front-page story, a full page inside the paper, an editorial and an op-ed column. The editors also chose a photo of Christie that made him look film-noir sinister.

Of special note was a convoluted article on a conversation that may or may not have happened and may or may not have included any relevant exchange between the governor and a former associate.

The headline on the piece was a master of innuendo without a smidgen of fact: “Potentially Explosive Detail in Bridge Scandal is Unlikely to Be Confirmed.” The paper should have included tin-foil hats so readers could decipher the coded message to partisans.

None of this is meant to suggest that Bridgegate isn’t newsworthy, or that Christie is blameless. Rather, the issue is one of proportion and fairness, not to mention at least a pretense of respect for evidence.

Compared to the unanswered questions about the deaths of four Americans at the hands of terrorists in Benghazi, Bridgegate is more chaff than wheat. Similarly, compelling evidence that the IRS denied conservative groups equal treatment is a far more important story about government abuse of power than a traffic jam.

But those stories reflect badly on a Democratic president, so the Times doesn’t have much interest in getting the truth, especially when there is a Republican they can turn into a piñata.