Former US secretary of state Henry Kissinger warned that Europe and the United States must unite to head off a "war of civilizations" arising from a nuclear-armed Middle East.
In an opinion column in the Washington Post, the renowned foreign policy expert said the potential for a "global catastrophe" dwarfed lingering transatlantic mistrust left over from the
"A common Atlantic policy backed by moderate Arab states must become a top priority, no matter how pessimistic previous experience with such projects leaves one," Kissinger wrote.
"The debate sparked by the Iraq war over American rashness vs. European escapism is dwarfed by what the world now faces.
"Both sides of the Atlantic should put their best minds together on how to deal with the common danger of a wider war merging into a war of civilizations against the background of a nuclear-armed Middle East."
Kissinger wrote that the big threat lay in the erosion of nation states and the emergence of transnational groups.
Iran was at the centre of the challenge, he said, with its support for Hezbollah, radical Shiite groups in Iraq and its nuclear program.
Washington must accept that many European nations were more optimistic about talks designed to convince Iran to halt uranium enrichment -- a process Tehran denies is aimed at making weapons, he wrote.
But in return, he said, Europe should accept the process must include a "bottom line" beyond which diplomatic flexibility must not go and a time limit to ensure talks did not become a shield for "developing new assaults."
In the article, Kissinger, national security adviser for former president
Richard Nixon, and secretary of state for Nixon and his successor Gerald Ford, warned the Lebanese Shiite militia Hezbollah was still dangerous, after its month-long conflict with Israel.
"Hezbollah's next move is likely to be an attempt to dominate the Beirut government by intimidation and, using the prestige gained in the war, manipulating democratic procedures," he said.
He concluded by noting that observers wondered whether, after the Cold War, trans-Atlantic ties could survive the loss of a common enemy.
"We now know that we face the imperative of building a new world order or potential global catastrophe. It cannot be done alone by either side of the Atlantic. Is that realization sufficient to regenerate a common purpose?"