The announcement last week by a UN tribunal that it would file indictments against four members of Hizbollah over the murder of Lebanese prime minister Rafik Hariri in 2005 drew the expected response.

Sheikh Nasrallah said in a fiery speech that he would not deliver his men, "not even in 300 years", and presented documents and videos that, according to him, proved Israeli influence over the tribunal.

The Hariri tribunal has been a major bone of contention within Lebanese politics for the past six years and the reason why the previous government fell nine months ago.

Despite this and Nasrallah's show of defiance, senior defence officials in Israel do not believe that Hizbollah will try to take advantage of these developments to launch an attack on Israel.

Last month, a new government headed by pro-Syrian Sunni leader, Najib Mikati, was formed in Beirut, with Hizbollah's backing. "Since Hizbollah wants to hold onto its weapons, it will not give its rivals a reason to say that those weapons are risking Lebanon," said an Israeli defence source.

Another reason is that the Iranian leadership wants to keep Hizbollah's missiles, which it supplies, ready for retaliation in case Israel attacks Iran's nuclear facilities.