Earlier this month, following a meticulous investigation, the Bulgarian government announced that two of the individuals responsible for the July 2012 bombing at the Burgas Airport, that killed five Israeli tourists and a Bulgarian bus driver, "belonged to the military formation of Hizbollah". This came around the same time that authorities in Cyprus prosecuted a Lebanese-Swedish citizen who had confessed to be a Hizbollah operative watching Israeli tourists as potential targets.
These two cases revived the long controversy over alleged operations conducted by Hizbollah on European soil, and triggered a new round of heated exchanges within the European Union on the question of putting Hizbollah on the EU list of terrorist organisations.
For the EU, naming Hizbollah a terrorist organisation is more than a battle of words: as of today, Hizbollah can legally raise money in Europe, and in some cases donations are even tax deductible. Within the EU, Germany is considered to be Hizbollah's centre of activity, with about 950 members operating in the country according to German intelligence. But beyond these facts, the EU's refusal to classify Hizbollah a terrorist organisation has also been a powerful tool for the party in its quest for international respectability, starting in the mid-1990s.
The United States has repeatedly urged the EU to take a stand. Following the unveiling of the Bulgarian case, for instance, Thomas Donilon, national security adviser to the US president, Barack Obama, wrote in The New York Times that the EU should add Hizbollah to its terrorist list.
But Washington's pressure campaign is likely to end the same way it has on previous occasions. In practice, adding Hizbollah to the list requires unanimity among the 27 member states of the EU and as before, there appears to be no consensus in sight.
Only two countries have explicitly supported the new initiative to put Hizbollah on the "black list": the Netherlands and the United Kingdom. The Netherlands designated Hizbollah as a terrorist entity in 2004. As for the United Kingdom, its government started putting Hizbollah's External Security Organisation under the category of terrorism in 2001 and went further to include its entire military wing in 2008.
The British experience with the Irish Republican Army and Sinn Fein, in Northern Ireland, surely plays a role in this debatable distinction between political and military wings. As many experts on Hizbollah know, this divide is fictional: leaders like Hassan Nasrallah or Naim Qassem have always emphasised that the Majlis Al Shoura, the centralising executive body of the organisation, has oversight over all its activities.
The two countries that are likely to oppose a major change in the EU's policy are France and Italy. Leaders from both expressed caution and although they did not dismiss the issue, abstained from firm declarations.
These positions reveal less a support for Hizbollah's agenda than a cautious strategic assessment of the fallouts of such a decision. Officials in Paris and Rome fear that if the EU were to antagonise Hizbollah, such a move may jeopardise the efforts of the UN Interim Force in Lebanon that has members from a dozen EU nations.
It is widely known that to keep south Lebanon quiet after the 2006 war, Unifil did not replace nor did it try to bypass Hizbollah; it coped with it, and sometimes co-operated with it. Not surprisingly France and Italy have the biggest contingents in Unifil, with Italy commanding the mission.
But the strategic assessment goes beyond troop numbers and deployments: the biggest unknown from an EU change on Hizbollah would be the effect on Lebanese power players.
An EU designation could put the current government at risk in a period already marked by increasing sectarian violence between Sunnis and Shias, exacerbated by the war in neighbouring Syria. Dominated by Hizbollah, the government has tried to distance itself from the Syrian crisis through a policy of so-called "disassociation".
But Hizbollah has barely complied with the principle of disassociating from the Syrian war. It has been offering more military support to the Assad regime and is now engaged in an open confrontation with the Free Syrian Army along the Syria-Lebanon border.
The view in Europe, then, is that not only would a terrorist designation put an end to Hizbollah's quest for international respectability, it could at the same time open a new window for clashes between Hizbollah and Sunni groups that might resemble the 2008 fights on the streets of Beirut.
Mr Nasrallah understands and exploits these European fears of clashes in Lebanon. In a speech on February 16, the Hizbollah leader eluded to the Bulgarian investigation but threatened those in Lebanon who might be tempted to pre-empt an EU decision and go after the movement.
In the end, the most likely outcome might be the targeting of a few individuals within the command structure of Hizbollah who would be charged with planning the Bulgarian attack. There is a precedent: in 2002 the EU added seven Hizbollah operatives - including its military commander Imad Mughniyeh - to its financial sanctions list for terrorism but refrained from condemning the organisation itself. In 2008, Mughniyeh was assassinated.
But this option would surely not satisfy the Obama administration as it would not completely tarnish Hizbollah's international outreach, both symbolically and financially.
Jean-Loup Samaan is a researcher on Middle Eastern affairs at the Nato Defence College