Hezbollah, an Iranian proxy and a non-state organization based in Lebanon, had fought the IDF in the 1980s and mostly in the 1990s when the Israeli military was deployed in Lebanon. In 2006, the two sides clashed again, for 34 days, a war that ended in a kind of a tie. They might fight again because of escalation or if Israel attacks Iran’s nuclear infrastructure, following an Iranian attempt to produce a nuclear weapon. It might happen if the July 2015 nuclear agreement will collapse completely after the United States already pulled out of it.
Israel’s evaluation of the duration and mostly the cost of a war with Hezbollah, in all levels, along with its other ramifications, will play a major part in Israel’s decision whether to bomb Iran’s nuclear sites or not.
Meanwhile, there is ongoing friction between Israel and Hezbollah, due to Israeli strikes in Syria, aiming at disrupting the transfer of advanced weapons from Iran to Lebanon, i.e., to Hezbollah. Hezbollah has suffered heavy casualties in the Syrian civil war, up to 2,000 and counting. The organization will require time to rehabilitate, so it does not seek to confront Israel for now. Yet a miscalculation by one or both sides might ignite a war no one wants. For example, if Israel bombs a convoy in Lebanon, one that carries weapons that came from Iran through Syria, then Hezbollah will retaliate against Israel, and the situation might get out of control.
The IDF, one of the most powerful militaries in its region, outnumbers and outguns Hezbollah in both manpower and weapon systems such as tanks, aircraft, etc. Yet Hezbollah has quite a significant hybrid force, which has anti-aircraft, anti-ship, and anti-tank missiles, hundreds of drones and above all up to 150,000 rockets and missiles. They have various warheads and some of which cover all of Israel. Hezbollah could fire more than a 1,000 rockets a day and maybe even more than that during a confrontation with Israel.
Israel has systems to shoot down rockets and missiles, such as Arrow and the Iron Dome. Yet Israel does not have enough of them to intercept most of Hezbollah’s rockets and missiles, so the IDF can’t rely on a purely defensive strategy. The Israeli Air Force has been training to launch thousands of sorties in Lebanon, but it might not be able to stop the pounding of Israel by Hezbollah. Accomplishing this kind of mission also requires boots on the ground, i.e., to carry out a major land offensive inside Lebanon.
In April 2018, the IDF published an updated version of "IDF Strategy" (the first one was published in 2015), which explains among others how the IDF plans to operate in the next war. In recent years, the military held many exercises, aimed against Hezbollah. The IDF, which had some setbacks in the 2006 war, is determined to perform better.
However, defeating Hezbollah once and for all is a tall order. Even if Hezbollah takes a major hit, the group, which is rooted inside the Shi’ite community in Lebanon, can always continue fighting with guerrilla and terror tactics. Israel will therefore seek more limited objectives, mostly to destroy Hezbollah’s rockets and cause the group heavy casualties, aiming at deterring it and other groups –primarily Hamas – from provoking, let alone confronting, Israel.
The IDF will penetrate several dozen kilometers into Lebanon. The IDF’s elite armor and infantry units, mostly the regular ones, will carry the burden of the offensive. Special Forces such as the 89th commando brigade will assist by launching raids behind the lines, collecting information, etc.
The IDF relies on reserves. Tens of thousands of them will be mobilized at the outset of the war, if they are not called for active service before the battles begin. Many might be called while rockets fall around them at their homes or on their way to their bases, where they get their weapons, vehicles, etc. Rockets might continue to strike them when they will move to the frontline. In that sense, it will be more difficult for them to do their duty, in contrast to former wars.
Israeli officials, both military and government, repeatedly warned about the danger of storing rockets in about 200 villages and towns in Lebanon. When rockets are launched from those places, the IDF will strike them hard, causing severe collateral damage. The civilians living there will be warned in advance, as soon as possible, to evacuate their homes immediately. Hopefully, they will be able to do that, for Hezbollah might order some of them to remain behind, to serve as human shields.
The IDF can inflict a major blow to Hezbollah by catching the group off guard. A massive surprise attack might be Israel’s best chance to handle the rockets and reduce Israel’s casualties. However, such an attack could cause significant collateral damage since the Lebanese population might not have sufficient time to escape from their towns and villages, where the rockets are stationed.
The IDF will have to engage in urban warfare, including underground, in tunnels. The military has been training for that in various ways. Its troops must be familiar with the terrain of Lebanon so they exercise in similar areas, in northern Israel. Cooperation between the difference corpses such as infantry and armor is another important factor the IDF has been working on, as part of the preparations to fight Hezbollah. The IDF will also use its advanced C4I (Command, Control, Communications, Computers, and Intelligence) network.
Hezbollah got stronger and bigger during the Syrian civil war. The group is now more like a military than an organization, but this could actually benefit the IDF. If Hezbollah fighters move in relatively large formations it will be easier for the IDF to find and attack them. Hezbollah also got accustomed to enjoying air supremacy and receiving air support from the Russian and the Syrian air forces while confronting Syrian rebels who had no aircraft. In a war against Israel, Hezbollah will be both without air support, and it will have to deal with a powerful air force. It might cost Hezbollah dearly if its men are not well aware of that.
The United States sees Hezbollah as a terrorist group. Prior to 9/11, Hezbollah killed more Americans than any other terrorist group. In the next war, Israel will require US support. On the diplomatic level, Israel will need the United States to stand by it in the UN Security Council. Militarily, the United States can provide Israel with weapons, ammunition and spare parts, without sending US troops.
The next round between Israel and Hezbollah might be much more destructive than the 2006 war. The IDF should try to reduce the cost to Israel by conducting an effective large-scale air, land and sea offensive. The best way is to do that in total surprise.