THE visit to Syria by United States Secretary of State James Baker III is the most visible symbol of a budding rapprochement that is already proving profitable to both Washington and Damascus. For Syria's President Hafez al-Assad, Mr. Baker's arrival Sept. 13 signals the beginning of the end of a long period of isolation that has left Syria alienated from the West and odd man out in the Arab world. The fruits of cooperation with the US and Egypt in containing Iraqi aggression could eventually include a larger voice for Syria in Arab affairs, as well as Western and Arab assistance to revive its languishing economy.
For the US, Syria's unexpected role in mobilizing Arab support has been crucial to legitimizing the presence of the huge international military force now assembling in the Gulf.
Buoyed by Syria's stand, US officials now talk hopefully of a ``Cairo-Damascus-Riyadh axis'' that could become an important force for moderation in the region after the Gulf crisis ends.
``The development of this axis is potentially very promising for regional conflict resolution and especially for the Arab-Israeli peace process,'' says US Ambassador to Syria Edward Djerejian.
Baker's visit is the most recent of a spate of contacts that have energized the US-Syrian relationship since the start of the crisis. President Bush has phoned twice to consult with Mr. Assad, while Mr. Djerejian has had several meetings with Assad, which is a sharp departure from the past.
One item on Baker's agenda is expected to be the deployment of additional Syrian troops in the Gulf. Some 3,000 Syrian soldiers are now said to be in Saudi Arabia, along with a token force of several hundred in the United Arab Emirates. According to Western sources, Syrian officials have asked several countries, including the Soviet Union, for help in sealifting at least 15,000 more troops to Saudi Arabia.
Baker is also likely to prod Assad on the main issue that has impeded Syria's relations with the US and several other Western nations: sponsorship of terrorism.
Tensions between Damascus and Washington peaked following the downing of Pam Am flight 103 over Lockerbie, Scotland, in December 1988. Suspicion has centered on Ahmed Jabril's Damascus-based Popular Front for the Liberation of Palestine - General Command. Although there has been no proof of Syrian complicity in the attack, there is a clear case of guilt by association.
US officials say Assad took a step in the right direction when, in January 1989, he promised to punish any group conclusively linked to the bombing. The US and other Western governments now look for Assad to go further by guaranteeing he will cease all support for terrorist groups.
Given his reputation as a radical Arab nationalist who has often undermined US positions in the Middle East, Assad has surprised many observers here by the determination with which he has placed Syria in step with the US in dealing with the Iraq.
For explanations, they look to the long history of bitter relations between Assad and Saddam Hussein and to the end of the cold war, which has made the US more important for Syria's strategic goals in the region.
Beyond this, Western sources say Assad believes that Saddam has recklessly jeopardized Syria's security by inviting a regional war that could draw in Syria's powerful neighbor, Israel. Assad also believes Saddam's invasion of Kuwait could make it harder to achieve his No. 1 foreign policy objective: the return of the Golan Heights seized by Israel during the 1967 Arab-Israeli war.
``Assad feels that Saddam has acted to undermine the principle of the inadmissibility of the acquisition of territory by force,'' says Djerejian. ``If that's left unanswered, it will do much to undermine the efforts of Assad to negotiate the return of the Golan.''
Whatever the reason, Assad's decision to commit Syrian forces to the defense of Saudi Arabia has not been without political risks.
Both Syrian officials and Western diplomats in Damascus dismiss recent reports of pro-Iraqi demonstrations in Syria as Iraqi-inspired disinformation transmitted through Jordan-based journalists. But most Western observers agree that support for Saddam is latent throughout Syria.
``There's a lot of support for Saddam because he's prepared to stand up for his rights as an Arab,'' comments another Western ambassador in Damascus.
There are also widespread reports that Assad's decision to send Syrian troops to the Gulf was met with initial opposition within the Syrian high command.
Sensitive to his unaccustomed role as ally of the US, Assad has dispatched teams of Baath Party leaders around the country to explain that Syria - not Iraq - is the savior of the pan-Arab ideal.
``The public line the Syrians are taking is that Syria must try to save the Arab world from Iraq and from itself,'' says a diplomatic source.
``Politically, we are taking the same line, but it's not a matter of siding with the US,'' a Syrian official says. ``We sent our troops because we do not want to let the crisis be in the hands of foreigners. We are there not to fight Iraq, but to ensure that there is an Arab role in solving this crisis.'' Syrian officials also disclaim any interest in a payoff for Syria's role in the Gulf.
Even so, Syria stands to gain handsomely when debts are tallied at the end of the crisis. Saudi Arabia has already offered at least $2 billion in compensation, Western sources say. Kuwait is said to have promised up to $500 million in contributions withheld from Syria during the Gulf war.
Improved relations with the West could also unfreeze $150 million in development assistance pledged by the European Community and restore economic aid that totaled $500 million annually before being severed in 1983.
Meanwhile, Washington is savoring the possibility of eventually working with rather than against Assad to solve regional issues after the Gulf crisis is over.
A Western source sizes up Syria's potential value to the West:
``Without Syria there can be no comprehensive Arab-Israeli peace settlement. Without Syria, there can be no settlement of the Lebanon civil war. Without Syria's cooperation, efforts to stop terrorism will be limited.''