A task force of 26 American and European leaders and academics, co-chaired by University President Lawrence H. Summers, issued a set of recommendations Friday urging the United States and its European allies to address their strained relationship by seeking common ground on policy issues.

The group said that in order to reinvigorate their frayed relationship, the allies must give top priority to forging mutually agreeable “rules of the road” on the use of force, transforming NATO to face the new foreign policy challenges of the 21st century and working together to promote peace in the Middle East.

Summers, who served as Treasury secretary under former President Bill Clinton, said he thought the report would play an influential role regardless of who wins the presidential election in November.

“I think there will be considerable interest both in this country and in Europe because of the bipartisan nature of the report,” Summers said. “I expect it will be something that will be very carefully considered by the next administration.”

The report, called “Renewing the Atlantic Partnership,” was sponsored by the nonpartisan Council on Foreign Relations (CFR). The task force was led by Summers and former Secretary of State Henry A. Kissinger ’50.

It marks Summers’ most substantive public policy role since assuming the Harvard presidency in 2001.

The report cites a deterioration of the relationship between the United States and Europe—one that it says was exacerbated, but not caused, by the war in Iraq—as a critical reason to address the issues pushing the allies apart.

“The transatlantic relationship is under greater strain today than at any point in at least a generation,” the report says. “The war in Iraq brought these strains to the point of crisis.”

The current tension between the allies, the report says, dates back to “11/9,” the day the Berlin Wall fell and began the fall of the Soviet Union, the nation which much of Europe and the United States had allied to oppose. The alliance then began to lose a sense of common purpose, thus becoming “a victim of its own success,” according to the report.

And the distance between the countries expanded with the terrorist attacks of Sept. 11, 2001 and the differing U.S. and European responses, the task force said.

To narrow the gap, the report recommended the countries develop a common approach for dealing with “irresponsible states” and come together on policies to make use of multilateral organizations.

The task force also laid out five principles for the alliance: understanding and supporting countries’ increasing integration into the European Union; formulating common strategies; realizing the alliance does not require equal power from each participating country; fostering cooperation through domestic leadership; and continuing to work together economically to reinforce political ties.

Professor of Government Andrew Moravcsik, who directs the University’s European Union Center, said the report was encouraging because it lays out a moderate, middle path for the allies.

“Realistically, one report can only do so much,” he wrote in an e-mail. “But it does show that moderate U.S. and European policies, balanced between right and left within the U.S. and taking account of distinct U.S. and European priorities and power resources across the Atlantic, can be constructive. It is up to politicians on both sides of the Atlantic to make it happen.”

Task force director Charles A. Kupchan ’80, who leads the CFR’s Europe Studies program, said the report could affect policy-makers and cited its balance as one reason it might be widely accepted.