"I think it will calm domestic tensions for a time," Young told AFP. "But I also think that the Syrian objective is to build on this so that they can return to a situation that more or less existed before their withdrawal in 2005."
Assad and King Abdullah were in Lebanon on Friday for an hours-long visit, their first since 2002, which was swiftly followed by Qatar's emir.
Assad's visit was particularly controversial as his country was widely accused of the bombing that killed Hariri and 22 others on February 14, 2005 in Beirut.
Damascus has consistently denied the accusations but nonetheless pulled its troops from Lebanon after the murder, following a 29-year presence.
The visit came with tensions rising after reports of an impending indictment by the UN-backed Special Tribunal for Lebanon (STL) against Hezbollah members for the assassination of Hariri, father of current Prime Minister Saad Hariri.
Ties between Saudi Arabia, which is close to the Sunni Muslim Hariri family, and Syria deteriorated in 2005 but have rekindled in recent years, with Saad Hariri himself visiting Damascus several times since taking office in November.
Analysts say the joint Syrian-Saudi visit was a clear message that Syria, along with Iran, a major backer of Hezbollah, still holds sway in Lebanon with Saudi Arabia's blessing.
"The main message of the joint visit is that the Saudis are legitimising a new role for Syria in Lebanon because there are certain problems that do not lend themselves to peaceful resolution," said Hilal Khashan, a political science professor at the American University of Beirut.
"The Saudis made it very clear that they may talk to the Americans and postpone the tribunal indictments, but they cannot do away with it because it is in the hands of the international community," Khashan told AFP.
Hezbollah chief Hassan Nasrallah this month revealed the UN tribunal probing Hariri's killing was poised to indict members of his party, slamming the STL as an Israeli project.
His deputy Naim Qassem on Friday said Hezbollah had the right to defend itself through all available means, and Nasrallah is expected to address the issue again next week.
Hezbollah MP Ali Fayyad on Saturday told AFP the militant party maintained the hope the Lebanese would "act responsibly" in the decisive weeks to come.
"We call on everyone to deal with the dangers facing Lebanon with the utmost seriousness," he said in response to a question on whether Hezbollah's stance against the tribunal was a warning of potential conflict.
"We hope this (summit) will help contribute to a terminal solution to the dilemma Lebanon is facing as temporary solutions only postpone the dangers," Fayyad said.
Nasrallah's statements have sparked fears of a repeat of the deadly events of May 2008, when 100 people were killed in clashes that erupted when the government announced -- and then repealed -- a crackdown on Hezbollah.
But Young, who is skeptical that the STL will find and try the masterminds behind the Hariri murder, downplayed the likelihood of violence.
"I think if there is one thing that came out of the meeting yesterday it is that there is a Syrian-Saudi agreement to avoid violence in Lebanon, which would primarily be between Hezbollah and Hariri -- in other words between the Shiites and the Sunnis," he said.