(USATODAY.com) - Nelson Mandela's memorial service Tuesday brought together -- briefly -- the leaders of two long-estranged countries: The United States and Cuba.
President Obama shook hands with Cuban President Raul Castro during the service at which both spoke.
The United States and Cuba have not had diplomatic relations with Cuba since the communist revolution led by Castro's brother Fidel more than 50 years ago.
This appears to have been only the second U.S.-Cuban leader handshake in the last five decades. Back in 2000, Fidel Castro shook the hand of then-President Bill Clinton.
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Fidel Castro backed Mandela's anti-apartheid efforts, and Mandela often expressed his admiration of Castro. Fidel Castro visited South Africa for a conference in 1998, years after Mandela's release from prison and election as president.
During Mandela's memorial service, Obama could be seen chatting with a variety of world leaders, including Afghanistan President Hamid Karzai.
Obama and Raul Castro were among the world leaders who spoke at the memorial.
"Mandela showed us the power of action," Obama said, "of taking risks on behalf of our ideals."
In his speech, Castro called Mandela "the ultimate symbol of dignity and unwavering dedication to the revolutionary struggle, to freedom and justice , a prophet of unity, peace and reconciliation."
At a 2009 conference, Obama shook hands with another prominent anti-American critic, then-Venezuelan leader Hugo Chavez.
From the Associated Press:
"Obama was greeting a line of world leaders and heads of state attending the memorial in Johannesburg. He also shook hands with Brazilian President Dilma Rousseff, who has clashed with Obama over alleged National Security Agency spying.
"The U.S. and Cuba have recently taken small steps toward rapprochement, raising hopes the two nations could be on the verge of a breakthrough in relations. But skeptics caution that the two countries have shown signs of a thaw in the past, only to fall back into old recriminations."