President Obama’s chummy open-mic exchange with Russian President Dmitry Medvedev yesterday sounded very much like his foreign-policy Etch A Sketch moment.

The two were finishing a conversation at the Seoul nuclear-security summit. Obama was referring to Moscow’s real power, incoming President Vladimir Putin, in comments made as reporters filed into the room for a photo opportunity.

Here’s what the leaders said, unaware that the press could hear:

Obama: “On all these issues, but particularly missile defense, this, this can be solved — but it’s important for him to give me space.”

Medvedev: “Yeah, I understand. I understand your message about space. Space for you —”

Obama: “This is my last election. After my election, I have more flexibility.”

Medvedev: “I understand. I will transmit this information to Vladimir.”

It certainly sounds like a promise that Obama’s recent foreign-policy toughness will fade away once he’s won re-election.

Remember: Early on, Obama announced a “reset” in US relations with Russia, scrapping an anti-missile project in Poland and the Czech Republic in favor of ambitious agreements with Moscow on nuclear-arms cuts.

We’re still trying to regain the trust of the Poles and Czechs — America’s most loyal European allies, who lived for too many decades under Russia’s boot to trust Moscow’s promises.

Then this year the reset was reset. Mutual accusations between Moscow and Washington culminated in a high-profile outburst when one of Obama’s top foreign-policy advisers, UN Ambassador Susan Rice, told the Security Council she was “disgusted” by Moscow’s veto of a resolution condemning Bashar al-Assad’s atrocity-ridden rule in Syria. Obama has recently toughened his rhetoric on Assad, who he’d courted earlier on. Will Washington be more “flexible” after November, assenting to the butcher’s continued reign?

Meanwhile, the administration has sought to strike a markedly more pro-Israel stance, especially when it comes to Iran’s drive to build nuclear weapons.

“Containment is not an option,” Obama vowed at a meeting of the pro- Israel lobby, AIPAC, earlier this month. And: “The US will always have Israel’s back.

Give me space. . . This is my last election. The meant-to-be-private words undermine every firm public utterance the preside* t has made in recent months.

Another cause for doubt: A Tunisian student asked Hillary Clinton last month about hardening pro-Israel statements in Washington. The secretary of state replied: “You will learn as your democracy develops that a lot of things are said in political campaigns that should not bear a lot of attention.”

In Seoul this weekend, Obama hopped over for a visit of the demilitarized zone separating the two Koreas. Comparing that division to the former separation of Germany, the president sounded almost Reaganesque, saying that unification will surely arrive, and “The Korean people, at long last, will be whole and free.”

But what about next year? Will he stick with that theme or go back to appeasing Kim Jong-un?

Yesterday’s open-mic remark was heard loud and clear by Poles, Czechs, Koreans, Georgians, Japanese, Taiwanese, Arabs who hate dictators, Iranians who are tired of mullahs who bankrupt them in pursuit of regional supremacy and Israelis who trust America as their only world ally.

The president’s detractors have long accused him of being too friendly with America’s enemies and downright hostile to our friends. In the last few months, he’s managed, eloquently, to dispel much of that concern. But how long will it last?

After my election, I have more flexibility. (Copyright 2012 NYP Holdings, Inc. 03/27/12)