Highest regarded by whom?
By me for one. However, I wasn't being very clear in my earlier post. He is highly regarded for his humanitarianism (in part due to his tireless work with Habitat for Humanity and his overall humility and honesty.
Below, I have outlined some of his accomplishments since his Presidency ended:
Notwithstanding perceptions while Carter was in office, his reputation has much improved. Carter's presidential approval rating, which sat at 31% just prior to the 1980 election, was polled in early 2009 at 64%. Carter's continued post-Presidency activities have also been favorably received. Carter explains that a great deal of this change was owed to Reagan's successor, George H. W. Bush, who actively sought him out and was far more courteous and interested in his advice than Reagan had been.
In 2002, President Carter received the Nobel Peace Prize for his work "to find peaceful solutions to international conflicts, to advance democracy and human rights, and to promote economic and social development" through The Carter Center.Three sitting presidents, Theodore Roosevelt, Woodrow Wilson and Barack Obama, have received the prize; Carter is unique in receiving the award for his actions after leaving the presidency. He is, along with Martin Luther King, Jr., one of only two native Georgians to receive the Nobel Peace Prize.
Bill Clinton secretly recruited Carter to undertake a peace mission to North Korea, under the guise that it was a private mission of Carter's. Clinton saw Carter as a way to let North Korean President Kim Il-sung back down without losing face.
Carter negotiated an understanding with Kim Il-sung, but went further and outlined a treaty, which he announced on CNN without the permission of the Clinton White House as a way to force the US into action. The Clinton Administration signed a later version of the Agreed Framework, under which North Korea agreed to freeze and ultimately dismantle its current nuclear program and comply with its nonproliferation obligations in exchange for oil deliveries, the construction of two light water reactors to replace its graphite reactors, and discussions for eventual diplomatic relations.
The agreement was widely hailed at the time as a significant diplomatic achievement.
In August 2010, Carter traveled to North Korea in an attempt to secure the release of Aijalon Mahli Gomes. Gomes, a U.S. citizen, was sentenced to eight years of hard labor after being found guilty of illegally entering North Korea. Carter successfully secured the release.
Carter and experts from The Carter Center assisted unofficial Israeli and Palestinian negotiators in designing a model agreement for peace–-called the Geneva Accord–-in 2002–2003.
Carter has also in recent years become a frequent critic of Israel's policies in Lebanon, West Bank, and Gaza.
Carter visited Cuba in May 2002 and had full discussions with Fidel Castro and the Cuban government. He was allowed to address the Cuban public uncensored on national television and radio with a speech that he wrote and presented in Spanish. In the speech, he called on the US to end "an ineffective 43-year-old economic embargo" and on Castro to hold free elections, improve human rights, and allow greater civil liberties. He met with political dissidents; visited the AIDS sanitarium, a medical school, a biotech facility, an agricultural production cooperative, and a school for disabled children; and threw a pitch for an all-star baseball game in Havana.
The visit made Carter the first President of the United States, in or out of office, to visit the island since the Cuban revolution of 1959.These are but a few of his accomplishments since his Presidency.