Thousands of fighters backed by Iran have volunteered to join Hezbollah in their conflict against Israel.

The Associated Press quoted officials in Iran and factions backed by Tehran as saying that thousands of fighters from Iranian-backed groups in the Middle East are ready to come to Lebanon to join Hezbollah in its battle with Israel if the raging conflict escalates into an all-out war.

Israeli officials threatened to launch a military attack in Lebanon if a negotiated end was not reached to remove Hezbollah from the border. Hezbollah Secretary-General  Hassan Nasrallah said – in a speech on Wednesday – that militant leaders from Iran, Iraq, Syria, Yemen, and other countries had previously offered to send tens of thousands of fighters to help Hezbollah, but he said that the group already had more than 100,000 fighters.

Iran says fighters from across the region will join it if war breaks out on the Lebanese-Israeli border, as thousands of such fighters are already deployed in Syria and can easily infiltrate across the porous border. Some groups have already launched attacks on Israel and its allies since the Israeli war on Gaza began on October 7.

An official in an Iranian-backed group in Iraq – without revealing his identity – told the Associated Press in Baghdad, “We will fight side by side with Hezbollah if an all-out war breaks out.” For his part, an official in an Iranian-backed Lebanese group – who also insisted on remaining anonymous – said that fighters from the Iraqi Popular Mobilization Forces, the Afghan Fatemiyoun, the Pakistani Zainab Young, and the Houthi group in Yemen could come to… Lebanon to participate in the war.

Qasim Kassir, an expert on Hezbollah affairs, said that the current fighting relies mostly on advanced technology, such as missile launches, and does not require a large number of fighters. However, he pointed out that if a war breaks out and continues for a long time, Hezbollah may need support from outside Lebanon.

Israel is also aware of the potential for an influx of foreign fighters. Eran Etzion, the former head of policy planning at the Israeli Foreign Ministry, said at a panel discussion hosted by the Washington-based Middle East Institute on Thursday that he sees a high probability of a multi-front war.

He added that there could be interference by the Houthis and Iraqi groups, in addition to the influx of large numbers of fighters from Afghanistan and Pakistan to Lebanon and the Syrian regions bordering Israel.