By Jonathan Wright

WASHINGTON (Reuters) - As Europe and the United States squabble again over how to run the world, academics wonder whether it's just a transitory flap or part of a long-term trend away from five decades as friends and allies.

After all, with the Cold War over 10 years ago and nebulous "terrorist" groups the main common enemy in sight, why should Americans and Europeans bury their differences for the sake of showing the world a false facade of unity?

Or will the bonds of history, religion and culture outweigh the disputes of the moment over, for example, the Middle East, a possible attack on Iraq, carbon dioxide emissions and the treatment of detainees from Afghanistan?

The United States may have started as an offshoot of European civilization but pundits on both sides of the Atlantic now often emphasize the culture gap between them -- on capital punishment, gun control, health care, the role of the state and energy consumption.

On the political front, the foreign ministers of three major European countries -- Britain, Germany and France -- have used unusually strong language this month about U.S. foreign policy, especially about President Bush's threats against an "axis of evil" comprised of Iran, Iraq and North Korea.

Europeans have become increasingly critical, too, of what they see as the Bush administration's neglect of the Middle East as the conflict seems to escalate out of control.

U.S. leaders have responded in kind, sometimes in a dismissive tone likely to aggravate the war of words. One analyst said members of the Bush administration appeared to take glee in signs of European pique.

EXCEPTIONAL REACTION

The divergence between Europe and the United States in fact dates back decades, at least to the French decision to withdraw from the military wing of NATO in the 1960s and conflict over deploying U.S. missiles in Europe in the 1980s.

The gap was bound to widen after the collapse of the Soviet Union in 1991, and the appearance of solidarity after the attacks on the United States on Sept. 11 was an exceptional reaction to exceptional events, the analysts said.

"What we see is a continuation and aggravation of that trend, now that the shock (of Sept. 11) has worn off," said Ivo Daalder, a senior fellow at the Brookings Institution.

Charles Kupchan, a senior fellow at the Council on Foreign Relations, said the drift apart was probably irreversible, even if it has accelerated under Bush.

"The United States is tiring of being Europe's protector and losing interest in practicing the liberal internationalism that has been in play for the last several decades," he said.

"The change is not a passing idiosyncrasy of George Bush but a broader demographic change. If the Democrats won, it would be different for a while but in 10 years demographic forces would push them in the same direction," he added.

Across the Atlantic, the Europeans are reasserting the independence they suppressed, firstly during the Cold War and then when they needed the United States to help re-integrate east and central Europe and the Balkans in the 1990s.

SAME BINDING POWER?

German Foreign Minister Joschka Fischer, whose country was a passive ally of the United States before the fall of the Berlin Wall, summed out that new attitude last week. "Alliance partners are not satellites," he said.

"It remains to be seen if the fear of terrorism provides the same binding power as fear of the Soviet Union," said Leon Fuerth, national security adviser to former Vice President Al Gore and now a professor at George Washington University.

"What has changed is that without the Cold War it has been a lot easier for each side to focus on differences because there was no price to be paid," added Antony Blinken, a senior fellow at the Center for Strategic and International Studies.

Fuerth defends the Clinton administration's record on holding the transatlantic alliance together and faults the Bush administration for failing to cultivate the relationship.

"You have to spend a great deal of quality time on it... You can't treat the alliance as if it will always be there and will always mend itself," he said.

"There are times when senior official of the Bush administration adopt a tone that is dismissive of the concerns of our allies and sometimes dismissive of the need for an alliance. They need to get past that," he added.

TEST OF THEIR METTLE

"I find it troubling that some (U.S. leaders) respond with glee when Europeans show their pique. They see it as a test of their mettle, and that really has to go," said Kupchan.

"If this is going to be a long struggle (against terrorism), you have to invest in the relationships. The Bush administration could do a much better job at that," said Lee Feinstein, a senior State Department official under Clinton.

A common argument in Washington now is that the tough talk by the Bush administration is meant to galvanize the Europeans into action on the countries in Bush's "axis of evil."

Instead of griping about U.S. unilateralism and over simplifications, the Europeans should offer practical suggestions on how to stop Iraqi rearmament and how to persuade North Korea not to export missiles, the argument goes.

Any attack on Iraq would inevitably follow months of consultations with Europe -- consultations which could even produce alternatives to an attack, the analysts said.

A common approach to Iraq would relieve the tensions in the short term but the list of disputes between Washington and Europe seems to grow longer month by month.

Beyond that, the prognoses vary widely.

"Americans know they are better off working with partners and Europe remains the first partner. I'm leery of looking at long-term trends but Americans and Europeans have more in common with each other than with any one else," said Blinken.

Kupchan disagrees. "It's a different political culture. Americans are much less interested in the institutions of multilateralism, much more interested in the narrow definition of national interest. I see this as irreversible," he said.