A Middle East expert predicts that the involvement of Iran-backed Hezbollah in the Israel-Hamas conflict would significantly alter the situation.

• Hezbollah functions as both a political party and paramilitary organization, and is classified by the U.S. as a terrorist group.
• The Shiite political party in Lebanon, with 62 seats in Parliament, and its Iran-backed proxy militant unit wield a significant amount of power.
• The Lebanese economy is in its worst crisis ever, with triple-digit inflation and a currency that has lost over 90% of its value since 2019. Nearly three-quarters of Lebanese people live below the poverty line.

The conflict in Gaza could spread regionally as a result of the exchange of fire between Hezbollah and the armed forces in northern Israel.

If an Israeli ground incursion occurs in the north of the Gaza Strip, the conflict may expand to include other regional actors such as Hezbollah and possibly Iran, according to analysts.

If Hezbollah joins the conflict in neighboring Israel, it will be a game-changer, according to Firas Maksad, a senior fellow at the Middle East Institute, who spoke to CNBC on Wednesday.

Hamas is a weak underling of Hezbollah, a much more powerful and widely recognized nonstate military, and this will be a game-changer not only for Israel but also for the entire region.

Political party and paramilitary group

Hezbollah is a political party and paramilitary group in Lebanon, with significant influence in the country's government. It has 62 seats in Parliament and is backed by Iran. The U.S. has designated it as a terrorist organization.

The "Party of God," or Hezbollah, was founded in Lebanon during its civil war in 1982 with Iran's support and the assistance of Iran's Revolutionary Guard. After the war with Israel in 2006, the group's military strength increased, making its military wing the dominant force in Lebanon, surpassing the country's army as the primary military power.

According to experts, Hezbollah lacks the domestic popular support it previously enjoyed in 2006 to launch a military operation against Israel during its current conflict with Hamas.

Joseph Daher, the author of "Hezbollah: The Political Economy of Lebanon's Party of God," stated to CNBC that Hezbollah has become a significant player in both Lebanese politics and the region, but the country's Christian community are critical of or opposed to the group.

The scale of the situation will depend on whether Hezbollah intervenes or not, according to Daher, who stated that the group has extensive experience in the Syrian military scene, as well as in Iraq and to a lesser extent in Yemen.

He stated that Hezbollah is "ideologically, politically, militarily, and economically linked to Iran," while also being an independent Lebanese actor.

According to Hilal Khashan, a professor of political science at the American University of Beirut and the author of "Hizbullah: A Mission to Nowhere," the militant group would likely be hesitant to fully engage in the conflict.

Despite Netanyahu's decision, Hezbollah will not launch an attack against Israel from south Lebanon because it will give Israel the excuse to destroy Lebanon. Iran has already conveyed to Israel and the U.S. through intermediaries that it will control Hezbollah.

On Friday, Naim Qassem, the deputy chief of Hezbollah, declared that his party was fully prepared to participate in the fighting, stating that behind-the-scenes calls from great powers, Arab countries, UN envoys, and direct and indirect messages urging them not to intervene would have no impact, as reported by Reuters.

Lebanon crisis

Lebanon is currently experiencing its worst economic crisis ever, with triple-digit inflation and a currency that has lost over 90% of its value since the start of the economic crisis in 2019. Nearly three-quarters of the Lebanese population now live below the poverty line.

The group, which has control over Lebanon with an iron fist, has significant political influence and controls most border crossings. It uses its power to block key political appointments. Experts say that if a fresh front in Israel for Hezbollah emerges, it could be devastating for the group, and Iran may not want to use its strongest international militia to defend Hamas in Gaza or Israel.

Hezbollah must consider public opinion in Lebanon, as its own constituencies are experiencing war fatigue and are under the pressure of Lebanon's financial collapse, according to Maksad.

The Biden administration has positioned a carrier strike group in the Eastern Mediterranean and sent the U.S. secretary of State to show solidarity with Israel as Netanyahu hints at launching a ground invasion in Gaza. Maksad stated that the U.S. is working to prevent Hezbollah and Iran from entering the conflict.

The USS Gerald R. Ford's deployment is an attempt by the administration to manage the conflict, according to him.

In the region, the threat of Hezbollah's armed force is significant, as professor Khashan states that it is equivalent to a medium-sized European army.

He stated that Hezbollah can easily defeat the Lebanese military or occupy Saudi Arabia, but he also pointed out that Hezbollah is trained for asymmetric warfare and has no chance against the IDF in the event of a total war.