FOR the first time, the release of a single hostage - college professor Robert Polhill - is being widely seen as the opening step in a process which, if it succeeds, should see all the remaining 16 or so Western captives go free. Shiite circles in Beirut believe the main impetus for the move toward settling the hostage issue once and for all comes from Iran's President Ali Akbar Hashemi Rafsanjani. It was his declaration in early March that he ``felt'' a solution to the affair was on the way, that set off the expectations which began to be met with the release of Mr. Polhill Sunday. It is from Tehran that the Beirut kidnappers, linked to the Iranian-sponsored Hizbullah, are feeling the real pressure to begin releasing their captives, Shiite sources say.
In their original announcement heralding Polhill's release, the kidnap group said the step was being taken in response to ``insistent calls by Iranian leaders, who are keen to make a goodwill gesture in order to begin bringing the hostage affair to an end.'' After President Rafsanjani's statement in March, the same group had immediately issued a defiant statement ruling out any release.
But Iran is not the only major player. Syria, too, is an important element in the hostage picture, both through its strong - if sometimes strained - alliance with Tehran, and through its military presence in west Beirut, the Bekaa Valley, and other areas where Hizbullah operates.
Syria is able to mobilize those assets in favor of a hostage release, and to act as a necessary mediator and buffer between the Western nations on the one hand and Iran and the kidnappers on the other, analysts and diplomats. The Syrians also have the ability to veto releases of which they disapprove.
But at present, the Syrians appear to be in concert with Rafsanjani in wanting to see the ``closing of the hostage file,'' a course that Syrian sources say Syrian President Hafez al-Assad urged on his Iranian counterpart in a message conveyed during a visit to Tehran by Syrian Foreign Minister Farouq al-Sharaa last month.
``We hope that this will pave the way for the release of all the hostages,'' Mr. Sharaa said Sunday, as he handed Polhill over to United States Ambassador Edward Djerejian in Damascus. ``Everybody knows the efforts that Syria deployed with Iran to ensure the freedom of the hostages. We will continue this work until all are freed.''
The Syrians may have several reasons for wanting to see that file closed. Government sources in Beirut say Damascus is acutely aware of the impact of change inside the Soviet Union - its superpower ally. ``The Syrians see the US emerging as the global power,'' said a source.
Over the past year and more, Syria has also been working closely with US diplomacy in tackling the challenges it faces in Lebanon, especially that posed by Gen. Michel Aoun, the hard-line Christian leader.
The Arab-sponsored peace plan for Lebanon, which is backed by Washington and with which Damascus is cooperating, envisages a reunified Beirut and the dissolution of the militias as early steps. There is no place in such a scenario for kidnappers and hostages, another strong reason for closing that file.
Nor are Iran and Syria alone in urging an end to the affair. Even Col. Muammar Qaddafi of Libya is chiming in.
When the radical Palestinian faction headed by Abu Nidal released a Franco-Belgian couple and their child in Beirut at Colonel Qaddafi's behest on April 10, observers discounted any direct link with the mounting speculation over releases by Iranian-backed groups.
But the parties themselves have chosen to interact publicly in a way that creates a general climate of d'etente on the hostage front. If there were suspicions that Iran, Syria, and Libya were linked in a clandestine ``kidnap cooperative'' in the mid-1980s, that process seems now to be going into reverse.
Abu Nidal's step was immediately praised by the Tehran Times and used as an example to urge other releases. Polhill had barely been free an hour before Qaddafi came out with another appeal for all hostages to be freed in accordance with the merciful precepts of Islam.
If the trend in that direction is strong, the potential pitfalls are many. An obvious problem is that both the Iranian and US presidents have to tread warily in approaching one another.
There may be a limit to how many unconditional and unrequited releases Rafsanjani can seek, analysts say, before hard-liners accuse him of pandering to the ``imperialists.'' But President Bush cannot be seen to take the ``positive, reciprocal steps'' sought by the other side without being accused of rewarding terrorists.
Hard-line elements in Tehran, headed by former Interior Minister Ali Akbar Mohtashemi, are clearly hostile to the process. It remains to be seen whether they, or their radical clients in Lebanon, can find ways - possibly violent - of trying to undermine it.