By Feras Dalatey , Maya Gebeily and Timour Azhari
DAMASCUS, March 17 (Reuters) - The United States has encouraged Syria to consider sending forces into eastern Lebanon to help disarm Hezbollah, but Damascus is reluctant to embark on such a mission for fear of being sucked into the war in the Middle East and inflaming sectarian tensions, five people briefed on the matter said.
The proposal to Syria's U.S.-allied government reflects intensifying moves to disarm Iran-backed Hezbollah, which opened fire
at Israel in support of Tehran on March 2, prompting an Israeli offensive in Lebanon.
The idea was first discussed by U.S. and Syrian officials last year, said two of the sources - both Syrian officials - and two others familiar with the discussions. All spoke on condition of anonymity because of the sensitivity of the matter.
The idea was raised again by U.S. officials around the time the U.S. and Israel began their war against Iran. The two Syrian officials said a U.S. request came shortly before the war began. A Western intelligence source said it was just after it started.
Reuters spoke to 10 sources for this article - six Syrian officials and government advisors, two Western diplomats, a European official and a Western intelligence source. All said Syria's Sunni Islamist-led government had been cautiously considering a cross-border operation but remained hesitant.
U.S. encouragement for a Syrian operation in eastern Lebanon and Syria's hesitation to carry one out have not previously been reported.
A U.S. State Department spokesperson declined comment on "private diplomatic communications", and referred Reuters to the Syrian and Lebanese governments for comments on their operations.
DAMASCUS OFFERS ASSURANCES TO LEBANON
Despite historic enmity towards Hezbollah and Tehran - both fought alongside Bashar al-Assad during Syria's 2011-24 civil war - Syrian President Ahmed al-Sharaa has moved cautiously since U.S.-Israeli airstrikes on Iran began on February 28.
One source, a senior Syrian official, said Damascus and its Arab allies agreed Syria should stay out of the war, and take only defensive measures.
Damascus has deployed rocket units and thousands of troops at the Lebanese frontier since early February, calling these measures defensive.
Syria's ministries of foreign affairs and information did not respond to requests for comment.
Responding to questions from Reuters, Lebanon's presidency said it had not received any "hint or notice from the U.S., the West, the Arab countries or Syria" about U.S.-Syria discussions on a potential cross-border operation.
Lebanese President Joseph Aoun had held a bilateral call with Sharaa, and a trilateral call also involving France's president, in which Sharaa said Syria respected Lebanon's sovereignty and had no intervention plans, the presidency said.
It said Lebanon coordinates with Syria on border arrangements but has never discussed Hezbollah with Damascus.
Lebanon's military said channels of coordination with Syria remained open "within the framework of addressing border issues and common security challenges", with the aim of preventing tensions or incidents and ensuring stability in the border area.
Prime Minister Nawaf Salam said Sharaa had told him "the reinforcement of the military presence along the Syrian-Lebanese border aims solely to strengthen border control and maintain internal Syrian security", and that Sharaa underlined the importance of continued coordination.
Aoun has pursued a policy aimed at securing Hezbollah's disarmament but Beirut has moved cautiously, with Hezbollah wielding a potent arsenal and enjoying significant support among Lebanese Shi'ite Muslims.
Sharaa has said he supports Aoun's efforts to disarm Hezbollah.
DAMASCUS SEES RISK OF IRANIAN ATTACK, MINORITY UNREST
The senior Syrian official said Washington had given the green light for an operation into eastern Lebanon to help Lebanon disarm Hezbollah - when the time is right.
But Damascus saw risks including possible Iranian missile attacks and potential for unrest among minority Shi'ites, threatening efforts to stabilise Syria after sectarian violence last year.
Two Western diplomats also said Washington had approved the idea of a Syrian cross-border operation against Hezbollah. The Western intelligence source and a European official said the U.S. had asked Syria's army to play a more active role countering Hezbollah in Lebanon, including via a possible incursion into the east.
The Western intelligence source and the European official said Syria's leadership was wary of entering Lebanon as this could inflame bilateral tensions.
A Syrian military official said there was no final decision yet on any possible operation inside Lebanon, but the option of intervening in the event of a conflict between the Lebanese state and Hezbollah remained on the table.
SYRIAN DOMINATION UNDER THE ASSADS
Syria long dominated Lebanon under the Assads, sending in forces in 1976 during the 1975-90 civil war at the invitation of President Suleiman Frangieh and controlling Lebanon's post-war politics until its withdrawal in 2005.
Any Syrian intervention could fuel sectarian tensions in both Syria and Lebanon, home to a mosaic of sects including Sunnis, Christians, Druze and Shi'ites.
In a March 13 interview with Lebanese broadcaster MTV, Syrian Defense Ministry spokesperson Brigadier General Hassan Abdel Ghani said the build-up at the border was a defensive measure. There was a high level of coordination with Lebanon's army, he said, and Sharaa supported the establishment of Lebanese state authority over Lebanon.
Last week, Syria's army said Hezbollah artillery shells landed in a border village. Hezbollah had said it had repelled an Israeli attempt to infiltrate Lebanon from the same village. Israeli officials said they were unaware of any such operation. The Syrian army said it was "considering appropriate options to take the necessary actions" in response.
(Additional reporting by Mahmoud Hassano in Damascus, Writing by Feras Dalatey and Tom Perry, Editing by Timothy Heritage)
