Former president Barack Obama and his wife Michelle board Special Air Mission 28000, a Boeing 747 which serves as Air Force One, at Joint Base Andrews, Maryland Thomson Reuters DUBAI (Reuters) - Gulf Arab states are quietly applauding the arrival in the White House of a hawkish leader opposed to their adversary Iran, even if they suspect Donald Trump's short temper and abrasive Tweets may at times heighten tensions in the combustible Middle East.

While many countries around the world listened with concern to his protectionist inaugural address, Gulf Arab officials appear optimistic. They see in Trump a strong president who will shore up Washington's role as their main strategic partner in a region central to U.S. security and energy interests.

In Gulf Arab eyes, that involves above all checking what they see as a surge of Iranian support for paramilitary allies in Syria, Iraq, Yemen and Lebanon and for fellow Shi'ite Muslims in Bahrain and Saudi Arabia's oil-producing Eastern Province.

It also means overlooking for now rhetoric about uniting "the civilized world against radical Islamic terrorism" in an address that critics said echoed George W. Bush's "crusade" against terrorism, a phrase which, for Muslims, evokes barbarous campaigns by medieval Christians against Islam.

Saudi Arabia in particular appears relieved at the departure of Barack Obama, who it felt considered Riyadh's alliance with Washington less important than negotiating a deal in 2015 to neutralize Iran's nuclear program.

The relationship is a pillar of the Middle East's security balance. But it has suffered since Riyadh took issue with what it saw as Obama's withdrawal from the region, and a perceived inclination towards Iran since the 2011 Arab uprisings.

"ANOTHER RONALD REAGAN"

John Locher/AP Images; Doug Mills/AP Images

There have been tensions over Syria, where Obama dismissed Gulf Arab urgings to give more aid to rebels fighting President Bashar al-Assad, who has survived thanks to Iranian and Russian backing.

"Perception is important: Trump does not look like the kind of guy who will bend towards Iran or anyone else," said Abdulrahman al-Rashed, a veteran Saudi commentator.

"If he behaves as he says, then we will see another Ronald Reagan, someone all the forces in the region will take seriously. That's what we have missed in the past eight years, unfortunately."

Some worry that Trump's Twitter habit - his rapid, unbridled messages of praise or blame - mean he is unsuited to handling the volatility of the Middle East.

Faisal al-Yafai, a columnist with The National newspaper of Abu Dhabi, said that while his use of social media could be a problem, Trump was unlikely to change.

"At some point down the line something will happen in the world that will require a careful response, a careful policy, and Trump will react emotionally. That is always going to be the worry. But that's his attitude. That's who he is. Those who like Trump like that aspect of his personality," he said.

Some Arab commentators see a political resemblance between Trump and Reagan, who also campaigned on the slogan of making America great again. Reagan was also a strong backer of the military, although in the Middle East his 1981-89 presidency was marked by extended crises involving Iran, Lebanon and Libya.

While few in the Gulf expect Trump to repudiate the Iran nuclear deal despite his threats to do so, most want Tehran pressured to roll back what Gulf Arabs see as subversion in fellow Arab states by a revolutionary theocracy.

"I think he is going to be very, very tough on Iran. He will be decisive," said a Gulf Arab businessman, noting he expected the deal-maker Trump would demand something in return.

FOREIGN POLICY

Saudi Arabia's King Salman attends a session of Saudi Shura Council in Riyadh Thomson Reuters

Moments after his speech, the White House website said the Trump administration would make defeating "radical Islamic terror groups" its top foreign policy goal and would develop a "state of the art" missile defense system to protect against attacks from Iran and North Korea.

That will be the job in particular of Secretary of Defense James Mattis, Secretary of State nominee Rex Tillerson, and CIA chief nominee Mike Pompeo, all well known to Saudi officials.

In particular Mattis, a retired Marine general known for distrust of Iran, is a familiar figure to Gulf Arab rulers.

A former leader of Central Command, which oversees U.S. military operations in the Middle East and South Asia, Mattis said in Senate confirmation hearings this month that Iran was "the biggest destabilizing force in the Middle East and its policies are contrary to our interests."

Such views play well with Gulf Arabs.

"We hope Trump can correct (Obama's) policy, and while we are not sure of that yet, his choices to run the administration all sound experienced," said al-Rashed.

MILITARY BUILD UP

On Syria, Yemen, Iran and Bahrain, arenas for a tussle for influence between Riyadh and Tehran, Obama's preference for dialogue appeared weak to some Gulf Arabs.

Trump's own vision of "peace through strength" may change that perception of a passive Washington, and encourage Gulf Arabs to press on with a military build-up that relies heavily on U.S. and European defense companies.

Any number of issues could yet disturb ties - Jerusalem, oil policy, perceived anti-Muslim prejudice, and a U.S. law allowing lawsuits against Riyadh over the Sept. 11 attacks.

One of the most explosive appears to be Trump's vow to move the U.S. Embassy from Tel Aviv to Jerusalem, which would upend decades of U.S. policy, and his appointment as ambassador a lawyer who raised money for a major Jewish settlement.

Israel and the Palestinians, who are seeking a state of their own, both claim Jerusalem as their capital.

POLARIZING LANGUAGE

A member of Iraqi Special Operations Forces (ISOF) carries a rocket launcher at the University of Mosul during a battle with Islamic State militants, in Mosul, Iraq, January 14, 2017. REUTERS/Ahmed Saad

"It would create a lot of chaos, a new intifada maybe," a Gulf source with knowledge of official thinking said, adding Trump would think long and hard about a move that would be "a huge burden on the peace process".

Another issue is Trump's policy of seeking to destroy Islamic State. Gulf Arab states agree with him on the goal, but use of polarizing language seen as demonizing Muslims, and reliance solely on military force, would raise objections.

Such language could also inflame militancy by hindering the hearts and minds effort needed to counter the thinking behind the violence.

"The worst part about the speech is that he will target Islam as a religion in the name of fighting what he called radical Islamic terrorism, a blank label that is meaningless," Tweeted Daham al-Qahtani, a Kuwaiti political analyst.

"If he goes back to the era of Bush, and 'you are either with us or with the terrorists', this polarized idea, and then also the idea that military forces can solve it, then I think we will find ourselves in a very difficult situation, with a war that is going to be unwinnable," al Yafai said.

(Additional reporting by Tom Finn in Doha)