Given that a 40-year embargo hasn’t worked very well, the visit to Cuba this week by former President Jimmy Carter is an appropriate attempt to improve human rights there and U.S.-Cuban relations. More than further blockades or congressional missile rattling, direct engagement, even if part of an unofficial meeting, suggests the Cuba problem is one to be solved rather than merely feared.

Cuban President Fidel Castro, who bedeviled Mr. Carter 22 years ago with the Mariel boatlift, declared that his visitor would have full access to the island, including a facility the Bush administration suspects of producing biological weapons. From his arrival in Havana and throughout his trip so far, Mr. Carter has repeatedly raised questions about human rights, free speech and “the alleviation of human suffering.”

Accounts of torture, false imprisonment and myriad other forms of abject cruelty have arrived in the United States along with the hundreds of thousands of Cuban exiles during the last four decades. Former President Carter will not and could not see all of the worst of Cuba, but he no doubt will speak forcefully on what he does see, and the response from President Castro could well begin the conversation necessary to advance the current level of relations the stone-age standoff that currently exists.

Mr. Carter has gained enormous respect since he lost the 1980 presidential election to Ronald Reagan; his international work for human rights and the promotion of democracy since then give him and this trip needed stature. Even the conservative, anti-Castro Cuban-American National Foundation sees value in the meeting. Joe Garcia, the foundation’s executive director, said in news reports, “The creator of the international standard in human rights is going to meet with the greatest violator of human rights in the hemisphere. He is a former president, and his role has to be significant, or it would not be worth risking his legacy.”

Mr. Carter is certainly aware that his trip poses political problems for President Bush and for the president’s brother, Jeb, who is trying to get re-elected governor in Florida and who depends on the Cuban-American vote. But nearly 20 years after the conversations between former President Reagan and Soviet President Mikhail Gorbachev irrevocably rewrote that superpower relationship, the time is well past for the United States to reopen its policy of nonengagement with Cuba.