|Hezbollah has called for a boycott of the tribunal investigating the assassination of Rafiq al-Hariri [EPA]
By calling for a boycott of the tribunal investigating the assassination of Rafiq al-Hariri, the late Lebanese prime minister, Hezbollah has drawn a line in the sand: collaborating with the investigation is paramount to collaborating with the US, Israel and all other external forces that are targeting the party.
For Hezbollah, the Special Tribunal on Lebanon (STL) has become no more than a tool to achieve what Israel failed to in the 2006 war - disarming the movement credited with the 2000 liberation of southern Lebanon from Israeli occupation.
Hezbollah has repeatedly accused the STL of being politically motivated, but this is the first time that it has called on all Lebanese not to cooperate with the international body.
This new position was triggered by what has come to be known as the Dahyeh (a southern suburb of Beirut) incident.
Last Thursday, two STL investigators, accompanied by a translator, arrived at a private gynaecology clinic to meet with the chief physician there. They were surrounded and hit by tens of women protesting against their presence.
The incident was condemned by Hezbollah's Lebanese rivals, the US and the United Nations as an example of Hezbollah instigated "obstruction of justice".
Hezbollah responded by saying that the investigators' request for the mobile telephone numbers of 14 female patients, some of whom are the wives and daughters of Hezbollah officials, crossed all lines and constituted an unacceptable intrusion.
Hassan Nasrallah, the Hezbollah leader, made a speech in which he said the incident had tested the movements' patience and calmly, but sternly, warned against cooperating with the tribunal.
Justice or intervention?
The reaction to the incident has underscored the depth of Lebanon's internal divisions. For some the STL is a symbol for "a quest for justice" for others a symbol "of flagrant Western intervention".
Hezbollah's rivals in the March 14 coalition charged that Hezbollah had orchestrated the attack on the investigators just as it had incited villagers in the south of the country to resist members of the French contingent of the United Nations Interim Forces in Lebanon (Unifil) when they conducted an exercise last June.
This may be true - Hezbollah is influential in both Dahyeh and southern Lebanon. But both incidents also confirm Hezbollah's claim that it has been targeted.
Moreover, even without Hezbollah's intervention it is rather unlikely that clients of the private clinic and residents of southern Lebanese villages would have willfully cooperated with the French Unifil contingent or the STL investigators.
The maneuver that was received so negatively in the south was designed to test Unifil's reaction to missile attacks on Israel from Lebanese soil and the real life drills included searching villagers' homes and asking them to identify members of Hezbollah.
The Dahyeh incident is of a different nature. Sending male investigators to a gynaecology clinic to ask for the mobile telephone numbers of female clients is insensitive and resented on private, social and political grounds.
In their criticism of Hezbollah's reaction, the group's Lebanese rivals have failed to consider how such an encroachment on their private lives ought to be explained to the clinic's patients. Furthermore, it seems highly unlikely that any Lebanese party would have defended the STL's actions had it involved their own families.
But this is not the issue. It is becoming clear that reactions inside Lebanon are not about the logic or nature of the act itself, but that Hezbollah's rivals are looking for any means by which to marginalise the powerful movement.
The reactions should also be seen in the context of leaked reports that the STL is preparing to indict Hezbollah members for the murder of al-Hariri - something Hezbollah categorically rejects.
The pending indictment, which has been postponed to an unknown date, has emerged as the main catalyst of internal Lebanese polarisation. For even though the STL has not made any public statement, both Hezbollah and its rivals have treated the leaks as a time bomb waiting to explode.
Last August, following Hezbollah's rejection of accusations that some members of the group were involved in the assassination, Bashar al-Assad, the Syrian president, and King Abdullah of Saudi Arabia made a rare one-day visit to Lebanon during which they helped to negotiate "a truce" between the country's feuding factions.
Since then Saudi Arabia has been involved in efforts to postpone the indictment or at least to convince Saad al-Hariri, the current Lebanese prime minister and son of Rafiq, to reject the pending indictment.
A short-lived reconciliation
For its part, Syria initially kept a low profile, seemingly content that the investigation had steered away from its original focus on Damascus. Saad al-Hariri's March 14 coalition also dropped their accusations against Syria, with the prime minister publically saying that they had been "politically motivated". But Damascus has recently become more vocal, unequivocally condemning the STL and pledging its support for Hezbollah.
But al-Hariri, according to well-informed Arab diplomats, has told some Arab leaders that he found "the evidence" implicating Hezbollah in his father's murder compelling. His exoneration of Syria has therefore been seen as partly aimed at creating a wedge between Damascus and Hezbollah, while setting the stage for an indictment of the movement.
But the reconciliation with Syria was short lived and ties between al-Hariri and Damascus deteriorated as his coalition stepped up the rhetoric against Hezbollah. For as well as delegitimising the movement, an indictment would serve to undermine Syrian and Iranian influence in the country and could ultimately be used to tie Syria or Iran to the murder if the US considered it politically useful to do so.
While March 14 has been cautious not to renew its attacks on Syria, the STL remains a serious source of contention between the neighbouring countries and Damascus is clearly disappointed that al-Hariri has not agreed to reject any potential indictment of Hezbollah.
Aware of the efforts to corner it, Hezbollah has vowed to stay put - bringing to mind the events of May 2008, when its armed men took to the streets of Beirut in a bid to force the government to revoke its decision to take over the party's communications network.
Hezbollah had made a commitment to the Saudi king and Syrian president not to resort to violence to solve internal problems but feeling the weight of the increasing pressure upon the group, Nasrallah appears to be keeping all his options open.
The battle over the STL in Lebanon has come to embody all of the internal and external conflicts that could rip the tiny country apart. It has also become the most valuable tool for the March 14 coalition, which is already using it to cut down Hezbollah - a group which has disrupted the Lebanese elite's sectarian power-sharing formula since it gained legitimacy as a resistance movement.
But Hezbollah has demonstrated that it is not easily intimidated and will fight back.
Lamis Andoni is an analyst and commentator on Middle Eastern and Palestinian affairs.
The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.