It was a surprisingly candid admission for a sitting American president: The US has, in fact, done wrong to other nations.

“Even with your adversaries, I do think that you have to have the capacity to put yourself occasionally in their shoes, and if you look at Iranian history, the fact is that we had some involvement with overthrowing a democratically elected regime in Iran,” President Obama told Thomas Friedman of the New York Times, hours after a historic nuclear deal was concluded with Tehran.

Obama was referencing the 1953 CIA coup that overthrew Mohammad Mosaddegh, a secular democratic leader who nationalized Iran's oil industry, ending decades of British control. But the president's history lesson didn't end there.

“We have had (sic) in the past supported Saddam Hussein when we know he used chemical weapons in the war between Iran and Iraq, and so, as a consequence, they have their own security concerns, their own narrative,” the president said.

The Reagan administration re-established diplomatic relations with the Iraqi dictator in 1980s, providing intelligence that facilitated Iraq's invasion of Iran. This part of the historical record is rarely brought up in the US domestic discourse on Iran and the Middle East.

Instead, the US tends to focus on their own grievances: The 52 Americans held hostage during the Islamic revolution, the antagonism toward Israel and the anti-Semitic rhetoric of some Iranian leaders.

But it's not just Iran. For decades, the United States faced off with another revolutionary regime – the communist government in Cuba. This summer, things have changed. The normalization of diplomatic relations with Cuba and the nuclear accord with the Islamic Republic promise to end two long-standing international confrontations.

“A willingness to empathize - not sympathize, but to empathize, to see ourselves as other countries see us - is a sea change in US attitude,” Philip Brenner, an expert on US foreign policy and Cuba at American University, told DW.

“It's very hard for us to do it, because we're so large and others countries are so small,” Brenner said. “We have a capacity to affect them much more than they can affect us.”

'We've been able to talk'

It's still too early to know what consequences the nuclear accord will have for the US, Iran, the Middle East and the broader world. But the relationship between Washington and Tehran has already changed, according to John Limbert, the former deputy assistant secretary of state for Iran. Through painstaking negotiations, Iran and the US have proven to themselves and the world that they're able to reach an agreement on a complex and politically sensitive subject.

“People can't admit it in public,” Limbert told DW. “But the fact that instead of doing what we were doing for 34 or 35 years - which was to threaten each other, to shout at each other, to insult each other - we've been able to talk to each other, not as friends, but talk to each other.”

“That is a change, whether you like it or not, it is a big change in the relationship,” said Limbert, who was held captive during the hostage crisis. In response to the hostage crisis, the US broke off relations with Iran in 1980 and has not restored them since.

Limbert doesn't believe the nuclear deal will have an immediate impact on the regional dynamic in the Middle East, which is plagued by a violent mix of religious and geopolitical rivalries. But he said the two countries' newfound ability to talk could open doors to resolving other complex problems over the long term.

For four years, the US and Iran have been on opposite sides of the Syrian civil war. Washington opposes Bashar al-Assad's regime, Tehran supports it. Increasingly though, the focus has shifted away from Assad and toward the Islamic State, a bitter enemy of both Tehran and Washington, creating potential room for cooperation.

'What's taken us so long?'

The US and Cuba have also proven they're able to talk instead of shouting, insulting, and threatening one another. Diplomatic relations have been restored more than 50 years after they were cut off. Washington's position toward the communist government in Havana was long a source of tension with other Latin American nations.

“The United States was long seen as a hovering giant and hegemonic power that could intervene anytime it wanted,” Brenner said. “The Cuban revolution was considered legitimate by every other country in the hemisphere.”

The restoration of diplomatic ties has removed a major source of antagonism between the US and the rest of the hemisphere, according to Brenner. At the Summit of the Americas in Panama, President Obama was welcomed by Latin American leaders instead of being confronted with hostility. He shook hands with Raul Castro and held a private meeting with the Cuban leader.

Brenner believes the restoration of ties with Cuba could open new avenues of cooperation in fighting drug trafficking and poverty as well as increasing trade.

Limbert has just one question when it comes to the thaw with Havana and Tehran: “What's taken us so long, why did we waste so much time bashing each other? We've been beating our chests for 35 years, and you know what the result of that is - a sore chest.”