No one is the other to the other to the sea whether on hemmed island or vast continent —Cuban-American poet Richard Blanco, at the flag ceremony in Havana

In the aftermath of inaugurating the reopened US Embassy in Cuba last week, Secretary of State John Kerry toured the Plaza San Francisco in Old Havana and hopped into the driver’s seat of one of the vintage American automobiles that still traverse the streets of the Cuban capital. The shiny black ’59 Chevy Impala had been restored, just in time for the secretary’s historic visit, by master mechanic Julio Alvarez Torres; his renowned taxi fleet, NostalgiCar, is one of the new, entrepreneurial businesses in Cuba’s rapidly expanding private sector. In a sense, the classic Detroit car is a moving symbol—not only of past US-Cuban relations, but their future potential for full restoration.

The past and the future were very much on Kerry’s mind during his dramatic one-day trip to Cuba. During the flag-raising ceremony under a blazing mid-morning sun, Kerry noted that the breakthrough in relations owed to a courageous decision by Presidents Obama and Castro “to stop being prisoners of history and to focus on the opportunities of today and tomorrow.” But that “doesn’t mean that we should or will forget the past,” he noted. “How could we, after all?”

In his speech, Kerry recalled the Bay of Pigs—he referred to the CIA-led invasion as “a tragedy,” forgoing an opportunity to acknowledge and apologize for a flagrant act of US intervention that continues to resonate in Cuba—as well as the 1962 missile crisis. During those tense “13 days,” he remembered, “we were unsettled and uncertain about the future because we didn’t know, when closing our eyes at night, what we would find when we woke up.” For more than half a century, Kerry stated, US-Cuban relations “have been suspended in the amber of Cold War politics.” The raising of the Stars and Stripes marked the official beginning of a full-fledged détente in the Caribbean.

To be sure, there remain hard issues that divide the United States and Cuba and that will be difficult to resolve. At their press conference in an ornate salon of the Hotel Nacional, Kerry and his counterpart, Foreign Minister Bruno Rodriguez, exchanged words over the politically charged subjects of human rights and democracy. Rodriguez fended off criticism of Cuba’s human rights record by pointing to gender and racial discrimination in the United States, as well as the ongoing killing of young unarmed African-Americans at the hands of white policemen.

Both sides, however, acknowledge that normal diplomatic relations have created a new framework for engagement—and a bilateral mechanism to conduct a dialogue about the issues that will need to be resolved before relations are fully normalized. Indeed, Washington and Havana have already established a joint commission to address various issues, which, according to Kerry, range from “easy”—re-establishing direct-mail service, environmental concerns, disaster-management planning, and counternarcotics collaboration, for example—to “the toughies,” which include an end to regime-change operations run out of USAID under the guise of “democracy promotion” programs, compensation for expropriated US properties, and the return of the US naval base at Guantánamo to Cuban sovereignty.

The most significant and contentious issue, however, remains the US embargo. The restoration of diplomatic ties, as Raúl Castro has pointed out, “does not mean that the heart of the matter has been solved,” since only Congress can remove the sanctions. With Republicans in control—and dedicated to negating any Obama initiative that serves US national interests—the needed votes to lift the embargo will prove hard to find. Yet even some Republicans are beginning to acknowledge that as Cuba continues its evolution away from a strict communist economic system, the blockade is blocking US support for modernization and reform. “By constraining Cuba’s economic links with the United States,” American University professor William LeoGrande recently wrote in Newsday, “the embargo is slowing Cuba’s transition to a freer, more open economy.”

As Cuban and US diplomats now begin lengthy, open-ended talks on the many issues that stand in the way of fully normal bilateral ties, members of Congress will take up key legislation to lift the embargo and end restrictions on the rights of US citizens to freely travel to—and indeed actually vacation in—Cuba. Support for these initiatives will come from newly created business lobbies, current and future travelers, and even Pope Francis, who is due to visit Cuba in mid-September, and then bring his blessings to fully normalize relations to Washington. President Obama has made clear that he, too, would like to visit the island.

A presidential visit to Cuba will go a long way toward consolidating Obama’s efforts to change US policy from a dark past of aggression to a brighter future of engagement. His secretary of state’s trip to Cuba has advanced that mission. “We are certain the time is now to reach out to one another,” Kerry concluded, speaking in both Spanish and English so Cubans would understand him, “as two peoples who are no longer enemies or rivals, but as neighbors.”