NEW YORK -- A vast transformation in the world order, years in the making, is taking the clearest shape right now in the Middle East, a region where the United States has devoted many resources in the 21st century, reported Newsweek on Wednesday.

In March, China helped arrange a peace deal between Iran and Saudi Arabia, taking the kind of broker role in the region long held by the United States, while Washington currently has no diplomatic ties with Tehran and relations with Riyadh have grown strained, it said.

"We bluster, we threaten, we menace, we sanction, we send the Marines, we bomb," Chas Freeman, a veteran US diplomat, was quoted as saying. "But we don't ever use the arts of persuasion."

Washington's "moment of diplomatic glory" is long over, and "what has happened is that the American ability to coerce is declining," said Freeman. "We seem to be approaching the world as though we still have an unchallenged authority that we imagined we did at the end of the Cold War."

"The world is changing; the kaleidoscope is in motion. We're trying to put all the pieces in place," said Freeman, who once served as former US ambassador to Saudi Arabia. "The basic aim of our foreign policy is retention of primacy, which is impossible. Nothing is forever. No great power is always supreme forever."