Having just barely avoided plunging the economy off a cliff, Republicans and Democrats ought to consider: Do we really want to put ourselves and the country through this again and again?

Or, can we resolve — it’s New Year’s, after all — to realize we have to live with each other for four years, then bargain seriously and get stuff done?

There is enormous work to do to avoid impending new disasters — a default on the national debt, a sudden plunge of federal spending — and to put the country on a path to long-term economic health.

The cliff deal merely forestalled an immediate income tax increase for 99 percent of Americans and maintained benefits for the unemployed.

It did nothing to solve the country’s long-term debt burden, stop entitlements for old people from robbing the young, reform the tax code or provide the investments in education, infrastructure and research that the nation needs to meet global competition.

On the other hand — kick-the-can exercise though it was — the last-minute, sleepless-night, fiscal cliff deal did demonstrate once again that the parties can come together to avoid imminent catastrophe.

And, by merely de-fanging the spending sequester for two months, it prolonged planning havoc in every federal agency from the Pentagon to the National Institutes of Health, where grants are being canceled and researchers laid off.

And it identified who the grown-ups in town are: people we might look to to avoid the next double-barreled crisis just weeks down the road and begin tackling the longer-term threats.

President Barack Obama is riding high, having won re-election and bludgeoned the GOP into agreeing to tax rate increases on the richest Americans.

Instead of gloating, drawing lines in the sand and setting the stage for more bitter partisan confrontations, he ought to act like Grown-Up-in-Chief and set up a Council of Adults to work on the big problems ahead.

He could deputize Vice President Joseph R. Biden Jr., a better face-to-face negotiator than he is, to start working right now with Senate GOP leader Mitch McConnell of Kentucky to bargain on how to avoid a debt ceiling/sequester repeat of last month’s fiscal game of chicken.

It’s pretty surprising that McConnell, pegged by the White House as the arch-obstructionist, would be the one to cut the deal that avoided the cliff.

It turns out that the real obstructionist is Senate Majority Leader Harry Reid of Nevada, who reportedly threw his own president’s compromise offer on tax hikes — covering those earning more than $450,000 instead of $250,000 — into his fireplace because it was inadequately left-wing.

And on the House side, the grown-ups are Speaker John A. Boehner of Ohio and Budget Chairman Paul D. Ryan of Wisconsin, who voted with just a minority of their fellow Republicans not to let taxes rise on everybody and send the economy into recession.

Some right-wingers are declaring that Ryan’s 2016 presidential campaign was ended with that vote, but that’s hooey.

Ryan has defined time and again what reform-oriented Republican policy should be, has shown a willingness to adapt his ideal health care and Medicare solutions in concert with inventive Democrats such as Sen. Ron Wyden of Oregon and now has shown courage at the cliff.

Ryan’s presumptive presidential rival, Sen. Marco Rubio, R-Fla., had no sooner hinted (at last month’s Jack Kemp Foundation dinner) that the GOP had to adopt a softer, “I care” image after 2012 than he joined the over-the-cliff gang, presumably assuming that 2016 primary voters will still be looking for tea party purity.

Boehner clearly is a grown-up, too. Even though he has been serially humiliated by Obama and his own GOP Conference, he has striven repeatedly to find workable deals and has been willing to risk his gavel to avoid national disaster.

His immediate subordinates, Majority Leader Eric Cantor of Virginia and Majority Whip Kevin McCarthy of California seem to think that the future of the GOP lies with the tea party.

If that’s true, we’re in for spectacles like the nominations of Nevada Republican Sharron Angle — which kept Reid in the Senate in 2010 — and other outliers who prevented a GOP takeover of the Senate in 2012, not to mention losing the presidency.

If Obama were to show — or let Biden show — flexibility on spending and entitlements, he might find McConnell, Boehner and Ryan willing to further buck the right-wing claque.

Obama has done a good job keeping his base under control, but if there is to be any hope of real problem-solving, he is going to have to risk outrage on the left as future (not present) entitlement benefits are adjusted.

He’ll have to rely on Democratic grown-ups besides Biden. Rep. Chris Van Hollen of Maryland and Senate Majority Whip Richard J. Durbin of Illinois fit the bill.

Practically every media commentator is predicting bitter trench-warfare and more last-minute catastrophe-avoidance (or catastrophic failure) as the future of American politics for as far as the eye can see.

The past — particularly the abysmal record of the 112th Congress — lends credence to that forecast. But it’s not inevitable.

If Obama wants to avoid it, he might begin with a quiet weekend Gathering of Grown-ups at Camp David.