Secretary of State John Kerry is welcomed to Geneva Jan. 21 by U.S. Charge de Affairs Peter Mulrean. (Gary Cameron/Associated Press)

Rifts exposed by a dispute over whether to include Iran in an international peace conference on Syria threatened to overshadow the long-awaited event as world leaders began arriving Tuesday in this pretty Swiss town.

The one-day peace conference Wednesday is expected to be more style than substance, an opportunity for the world finally to show that it is taking action on Syria after nearly three years of bloodshed. Representatives of more than 30 countries will hear speeches supporting the goal of a negotiated settlement to the war, then depart.

The real work will begin in Geneva on Friday, when it is hoped that the two opposing sides will hold their first face-to-face talks, in the presence only of mediators from the United Nations.

The furor that erupted over the invitation to Iran extended by U.N. Secretary General Ban Ki-moon has come as a reminder that even the world powers sponsoring the event don’t agree on what it is about or what it is supposed to achieve.

In an effort to ease the tensions, Secretary of State John F. Kerry went straight into a meeting with his Russian counterpart, Sergei Lavrov, after arriving Tuesday night in Montreux, which is better known for its jazz festival than international diplomacy.

Kerry also met with Ban and the U.N. envoy for Syria, Lakhdar Brahimi, to smooth over the friction created by Monday’s confrontation over whether Iran would be included. The invitation was rescinded under intense U.S. pressure.

Iran blamed the United States for the retraction of its invitation, saying it proved that the United Nations is still dominated by big powers, in a reminder of the deep strains that still underlie Tehran’s relationship with Washington despite recent progress on an agreement to curb Iran’s nuclear program.

Syria also appeared displeased by the outcome, which means its staunchest ally will not be present at the event. Syrian Foreign Minister Walid al-Moualem expressed “reservations” about attending the talks before leaving Damascus for Switzerland, according to journalists accompanying him quoted by Lebanese television stations, ahead of his arrival Tuesday night in Montreux.

Few expect concrete results from this round of diplomacy, widely referred to as “Geneva 2” because it is taking place under the terms of a 2012 Russian-U.S. blueprint for ending the crisis known as “Geneva 1.”

“Everyone knows that the most likely outcome of Geneva 2 is Geneva 3, Geneva 4 and so on,” said Salem Zahran, a journalist and analyst who is close to several figures in the Assad regime.

President Bashar al-Assad, buoyed by months of small but steady military gains against the rebels, has made it clear he regards the conference as an opportunity to affirm his hold on power in the name of fighting terrorism.

Moualem plans to appeal for support for Assad from the delegates by outlining the threat posed by the al-Qaeda-linked militants who have steadily gained ascendancy in the rebel-held north of the country, according to people familiar with government thinking who travel between Beirut and Damascus.

A shadow delegation of ­Syrian military and security ­officials is bringing dossiers of information on wanted al-Qaeda terrorists in a further bid to lure the West into reorienting its support away from the opposition and toward the regime, one of those people said.

Assad’s opponents, however, have agreed to participate only on the condition that Assad’s removal is the main goal of the event.

Their cause was bolstered on Monday by the disarray over the invitation to Iran, which exposed international divisions over Syria that are almost as pronounced as those within the war-ravaged country.

U.S. support for the Syrian opposition’s insistence that Iran should not attend offered some vindication to those parties, which had been deeply divided over whether to attend at all. Opposition groups had threatened to withdraw from the talks unless the invitation was rescinded, opposition supporters and diplomats said.

The withdrawal of the invitation enabled the opposition to demonstrate to doubters that it does have assurances from its allies that the conference represents a serious effort to discuss ways to replace Assad.

“It gave them a small victory,” a Western diplomat said, speaking on the condition of anonymity in order to talk more candidly.

Whether the talks will broach the issue is in question, however. Diplomats and U.S. officials have cautioned that breakthroughs are unlikely. Rather, they say, efforts will focus on an attempt to forge confidence-building measures such as local cease-fires and efforts to deliver humanitarian aid that might help build wider support for a peace process ahead of future talks.

Many ordinary Syrians expressed the hope that at least some sign will emerge of an end to the nightmare that Syria’s iteration of the Arab Spring has become.

“People just want it to end. They don’t care how,” said a Damascus resident interviewed while on a recent visit to Beirut.

Suzan Haidamous and Susannah George in Beirut contributed to this report.