By William Maclean

DUBAI, May 22 (Reuters) - The images from the same night broadcast around the Middle East speak as loudly as the words. On the one hand: the young people of Iran, dancing in the streets to mark the re-election of a pragmatist, men and women together.

On the other: the president of the United States, swaying through an all-male "sword dance" under the stars with the absolute rulers of Saudi Arabia, where publicly calling for any form of political change risks prosecution.

President Donald Trump told admiring Arab absolute monarchs and military strongmen in a gilt chamber at the weekend that he wanted "peace, security and prosperity", and the United States was not there to tell them how to run their own countries.

He joined them in berating their arch-foe Iran, and signed a $110 billion arms sale to Saudi Arabia that put him firmly on one side of the sectarian divide fuelling most of the Middle East's wars.

The contrast between the two scenes was noted by Iran's newly re-elected president, Hassan Rouhani, who has sought to reach out to the West while batting back hardliners at home.

"Buying arms or building weapons won't make a country powerful," Rouhani told a news conference on Monday.

"The foundation of power is national strength and this only happens through elections. Trump saw millions of Iranians took part in an election, but he visited a country whose people have not seen a ballot box and don't know what an election is."

"PRE-OBAMA ERA ON STEROIDS"

Trump's attempt to orchestrate a Muslim and Arab coalition against Iran was a repudiation of the regional policy of his predecessor Barack Obama, whose administration held the first direct talks with Tehran since the 1979 Islamic Revolution.

Although Washington and Tehran were still a long way from normalising their relations, Obama reached an accord to lift sanctions in return for Iran curbing its nuclear programme, which Trumprepeatedly slated as "the worst deal ever signed".

By swinging American policy back to firm support for the Sunni Arab states, Trump has jettisoned that carefully constructed balance, said Jean-Marc Rickli, Head of Global Risk and Resilience at the Geneva Centre for Security Policy.

"We are back in the pre-Obama era, on steroids," he said. "Under Obama you had this attempt of the USA playing the external balancer in the region. Now the regional balancer has gone. The balancer has chosen his camp."

Just as dramatically, Trump also repudiated the policies of Obama's Republican predecessor George W. Bush, who promised to spread democracy across the Middle East in a landmark 2003 speech that declared "freedom can be the future of every nation".

Trump told his audience of autocrats: "We are not here to lecture you. We are not here to tell other people how to live, what to do, who to be or how to worship."

COMPLEX MIDDLE EAST

Washington's alliance with the mainly Sunni Muslim countries of the Arab world against Shi'ite Iran is decades old. But in practice the United States has had to improvise in recent years when choosing its friends in a more complex Middle East, where enemies can appear on either side of the sectarian divide.

Washington and Tehran are still frequently on opposing sides, most notably in Syria, where Iran supports the government of President Bashar al-Assad. But elsewhere, notably Iraq, U.S. forces are fighting on the same side as Shi'ites close to Iran.

Obama's outreach to Tehran reflected that reality. But those subtleties were cast aside on Sunday when Trump nodded approvingly as Saudi King Salman described Iran as the "tip of the spear" of terrorism in the Middle East.

A senior U.S. official defended the initiative, citing "a common threat from terrorist organisations as well as from Iranian subversion throughout the region".

In fact, most of the militant groups U.S. troops have fought in Iraq, Afghanistan, and elsewhere since the Sept. 11, 2001 attacks on New York and Washington, such as al Qaeda, Islamic State and the Taliban, are Sunni Muslims who consider Shi'ite Iran their enemy.

The timing of Trump's uncompromising call for a U.S.-backed axis against Iran was particularly awkward because it coincided with the re-election of Rouhani, swept to a second term on his promises to seek rapprochement with the West.

Although democracy in Iran has clear limits - all candidates must be vetted by a hardline body and the unelected supreme leader can veto policies of the elected government - it still goes further than in most of the countries that attended Trump's speech, a fact noticed across the region.

U.S. arms deals for Iran's Sunni foes help bolster the case of Rouhani's hardline opponents, who say any detente with the West is dangerous folly.

The Riyadh summit showed that the "passivity" of Rouhani's government "has emboldened the enemies of Iran," wrote Hossein Shariatmadari, editor-in-chief of Kayhan, a newspaper closely associated with security hardliners who opposed Rouhani.

"Small and weak countries that could not imagine a fight with Iran, are now publicly talking aboutforming a military alliance against it."

The Revolutionary Guards (IRGC), the powerful Iranian security force that supported Rouhani's hardline opponent in the election, has the power to stir up confrontation across the region to undermine Rouhani at home.

"All the indicators point to a further arms race in the region and on the rhetorical level we are on a path of escalation," said Rickli. "You just need a small trigger that can escalate the situation on the ground.

"I would not be surprised to see an increase in hostilities in Syria and Yemen. Also, the IRGC might want to foster pro-Shi'a groups in Bahrain and some parts of Kuwait to regain power after the elections," Rickli said.

Putting a huge arms deal at the centre of the visit also plays into the hands of foes who say U.S. policy is driven mainly by money.

Saudi Arabia is both the world's biggest exporter of oil and one of the world's biggest importers of military hardware made in the West. Trump boasted about the jobs that would be created at home by the arms deals he signed.

"We will make sure to help our Saudi friends to get a good deal from our great American defence companies, the greatest anywhere in the world," Trump said in his speech.

"Doubling down on Saudi Arabia has a lot to do with trade and investment considerations. The supporting allies, anti-terrorism and anti-Iranian rhetoric provides a cover for that," said Richard Dalton a former UK ambassador in the Middle East.

But the policy could be counter-productive, he said.

"Furthering more enmity with Iran, rather than seeking common ground and interests at a time when Iran is ready to reach out diplomatically on the region's long-term problems, is going to work against the long term aim of a peaceful and stable Middle East." (Additional reporting by Katie Paul in Riyadh and Bozorgmehr Sharafedin in London; editing by Peter Graff)

© Reuters News 2017