Possibly the most significant US steps have been the loftily named Syrian Accountability Act and the Lebanon Sovereignty Restoration Act, which US President George Bush signed into law in December 2003, expected to impose sanctions on Damascus.
The US legislation demands Syria withdraw its estimated 20,000 troops from Lebanon. It also calls for an end to its support for "terrorism" and a halt to alleged development of weapons of mass destruction and medium and long-range missiles, charges Damascus denies.
Syria is the main powerbroker in Lebanon and wields a firm grip over Beirut's security apparatus and government.
US Secretary of State Colin Powell, on a visit to the Gulf, reiterated what have become almost feverish calls for a withdrawal, so that Beirut can enjoy "full sovereignty".
State Department spokesman Nabil Khury, who was responsible for liaison between Washington and the Arab media during the US-led war against Iraq, again emerged in the region to send a US message.
"The old arguments that this presence was necessary as collateral for recovering the Golan or to protect Syria's flank in the event of an Israeli attack are now obsolete and out of date," he told Lebanon's French-language L'Orient-Le Jour newspaper.
Lebanese opponents of Syria's presence have increasingly voiced their demands for a full Syrian withdrawal, emboldened by the death of Syrian leader Hafidh al-Asad in June 2000. University students have frequently organised mass rallies, which often end in clashes with riot police and dozens of arrests.
"Particularly in the field of foreign policy, the Syrians essentially have veto power over most Lebanese initiatives"
Middle East editor,
Foreign Policy in Focus Project
However, it is highly unlikely that US policymakers have taken up a crusade to restore sovereignty to Lebanon, said Arab and Western analysts.
These calls "should be seen more as an exertion of American hegemony rather than any kind of principled support for international law or Lebanese sovereignty," said Stephen Zunes, Middle East editor for the Foreign Policy in Focus Project, a US thinktank.
"If we were concerned about Lebanon's sovereignty we would not have supported 22 years of Israeli occupation," he added.
US demands for a Syrian pullout are part of an overall strategy to pressure Damascus to change its regional politics, said analysts.
"Particularly in the field of foreign policy, the Syrians essentially have veto power over most Lebanese initiatives," said Zunes. "They do exert quite a bit of influence on that country’s policies, I think analogous to the Soviet Union’s influence on its eastern European satellites during the Cold war."
Syrian soldiers left positions in
Lebanon which borders Israel
Lebanese political commentators agreed.
"A lot of the Lebanese politicians currently are there because they enjoy backing from Syria. And the more nice things they say about Syria, the more they will stay in office," said one observer who asked not to be named.
Zunes believes Syria is the latest target of US "antipathy" because of its opposition to what he describes as American dominance in the region.
"Since the removal of Saddam Hussein, Syria is one of the very, very few remaining Arab nationalist governments that try to put its own self-interests ahead of Washington," says Zunes.
Former US Secretary of State Henry Kissinger engineered Syria's troop presence in Lebanon in 1976.
Al-Asad became involved in Lebanon to rein in Palestinian resistance fighters and their leftist Lebanese allies from defeating Christian militias. Kissinger played on al-Asad’s fears that if Damascus did not crush the Palestinians, Israel would be more than willing to carry out the task - a scenario al-Asad wanted to avoid.
Riot police use water cannons and
batons to disperse demonstrators
Israeli troops moving freely in Lebanon would make it easier to attack Syria. Thus, the Arab League authorised Syrian forces to enter Lebanon in May 1976, and they have never left.
The civil war finally came to an end following the 1989 Taif accord, a Saudi Arabia-sponsored Arab League effort. It called for a complete Syrian military redeployment from Beirut and other major cities in the Beqaa Valley by 1992. However, it set no date for a full Syrian withdrawal, saying such talks would occur only after Arab-Israeli peace had been brokered.
"The Taif agreement has only been partially applied in terms of the Lebanese-Syria issue," said a Beirut-based Middle East political analyst who asked not to be named.
After Israel’s withdrawal from south Lebanon in May 2000, following a 22-year occupation, Syrian troops have redeployed four times from Beirut and mountain areas. But many of these forces have only shifted to the Beqaa valley in eastern Lebanon.
Scramble to 'victory'
The Bush administration is scrambling to score a success in the region after Iraq continues to plunge into chaos a year after the US-led war against it. One of the justifications for the war was to bring "democracy" to Iraq.
"If they are able to get a Syrian withdrawal from Lebanon they can claim that Lebanon is a victory, that they’ve restored sovereignty to another Arab state," said a Lebanese Middle East political analyst who asked not to be named.
"They can say: 'Look, we’ve already re-established democracy in Lebanon, we're working on the one in Iraq, we're working on the one in Syria'; they can have something to show," he said.
Divide and conquer
Washington "is trying to push Syria from all directions: from Israel, from Lebanon, from Turkey, from the Kurds, from sanctions to get it to kneel," said Dr Paul Salem, a Beirut-based regional analyst.
Tensions in northeastern Syria
have quietened in recent days
Earlier this month, Kurds clashed with Syrians in the northeast part of the country after Kurdish riots swept the town of al-Qamashli killing at least 14 people.
The violence in al-Qamashli, an ethnically mixed town near the Turkish and Iraqi border, ended after Interior Minister Ali Hajj Hammud flew to the area to take control and the authorities threatened those responsible with the "severest punishments".
These incidents are extremely serious and pose the gravest threat to the Syrian government since Kurdish uprisings in 1979 in neighbouring Iran, warned Salem.
"It’s possible that the US, having toppled Saddam, is now free to meddle with Syria and encourage the Kurds ... and let them go ahead and make trouble," said Salem.
Syria is home to some 2 million Kurds.
Iraq’s own Kurdish population supported the US-led invasion. Kurdish militias or Peshmerga fought under the command of US occupation forces to topple Saddam.
"Given the Kurdish empowerment in northern Iraq ... it’s not unnatural that they look to the West and say: 'Look, we've got a million, a million and a half [sic] of our brothers over there. Let’s send them guns and money and when we finish with this over here, let’s turn our attention somewhere else'," said one Lebanese analyst.
"Given US hostility to Syria, given the Sunni opposition within Syria and the tight spot Sunnis are in within Iraq, all of that is a very precarious powder keg," he said.
Under US and British defence, Kurds have enjoyed autonomy in northern Iraq since 1991. Kurdish calls in Iraq for further autonomy have stirred fears in Turkey and Syria that their own Kurdish populations will demand autonomy.
Washington's staunch regional ally, Israel, will also reap the benefits of a Syrian pullout from Lebanon.
Too close for comfort: No love
lost between Syria and Israel
Damascus provides backing for the Lebanese resistance group Hizb Allah, which spearheaded efforts to oust Israeli occupation forces from south Lebanon.
A Syrian withdrawal from Lebanon would presumably reduce Damascus' influence on the resistance group, which Washington includes on a list of so-called "terrorist" organisations.
"The United States very much wants Lebanon to make some kind of separate peace with Israel now that there are no longer outstanding issues regarding the occupation, with the possible exception of the Shebaa Farms," says Zunes.
Lebanon and Syria have insisted on maintaining a bilateral peace track with Israel.
And while US calls for a troop pullout could lead to a Syrian military disengagement from Lebanon, it is unclear whether Washington will demand Damascus should release its political grip over Beirut.