Hizbollah doesn't have a large "army." Only a few thousand trained and trustworthy gunmen. About 20 percent of these have been killed or wounded so far. About half of the 70,000 man army is Shia, a consequence of depending on Syria to help form and train the army. That's one reason why most Lebanese don't trust their own army, and why the Israelis don't accept the Lebanese offer to send 15,000 of their soldiers into southern Lebanon to take over from Hizbollah. While the Shia Lebanese soldiers aren't all Hizbollah members, those that are Shia know that Hizbollah can reach their family members. Hizbollah is a terrorist organization, and good at that sort of thing.
While no Lebanese want another round of civil war, if it did happen, it would be everyone against the Hizbollah led Shia. The result would be up to half the Shia population exiled in Syria, and Shia power in Lebanon broken for a long, long time. The Shia sect (Alawites) that runs Syria wouldn't mind a few hundred thousand Shia refugees in their midst, as Shia are only about ten percent of Syria's population. The Sunni Arabs who are the majority of Syrians might mind. Iran would come through with lots of money to make it all better, and keep the Shia in charge of Syria.
Israeli troops advancing into southern Lebanon are finding a lot of late model Russian weapons. Especially abundant are recently manufactured Russian anti-tank missiles. Three post-Cold War Russian missile systems have been found in large numbers. These include the 9M111 Fagot, which has a 25 pound missile fired from a 24 pound launch unit for up to 2,000 meters. Then there is the 9M133 Kornet, a replacement for the 9M111. This is laser guided missile with a range of 5,000 meters. The launcher has a thermal sight for use at night or in fog. The missile's warhead can penetrate 1200 mm of armor, which means that the front and side armor of the Israeli Merkava tank are vulnerable. The missile weighs 18 pounds and the launcher 42 pounds. Then there is the 9M131 Metis 2, which is a 30 pound missile, with a 1,500 meter range. It is fired from a 35 pound control unit, that has a thermal sight. Missiles and launch units have been found in bombed out buildings. The 9M131 can be fired from inside buildings. The missiles are used to take long range shots at Israeli infantry, as Hizbollah knows that, up close, their gunmen tend to lose quickly, and with heavy casualties, to the better trained Israelis. Russia has been selling these new missile systems to Syria and Iran, and this is the first real combat test of these systems. A few Israeli tanks have been hit, but most of the missiles have been fired at Israeli infantry, causing over a hundred casualties. Israel won't release details of these operations until after the war is over, but has admitted that most of their casualties in southern Lebanon have come from these Russian missiles.
Israel is moving sufficient troops, to the Lebanese border, to clear an area about 20 kilometers north of the border. This would severely limit the ability of Hizbollah to fire 122mm rockets into Israel. The Israelis would systematically clear civilians and Hizbollah fighters out of the area. Hizbollah has already lost hundreds of millions of dollars in assets (buildings, vehicles and equipment). The Israelis are holding off on the "20 Kilometer Zone" operation to see if the UN can work out a ceasefire deal. That would have to include a force of "trustworthy" (Western) peacekeeping troops in southern Lebanon. There would have to be peacekeepers who could, like the Israelis, fight Hizbollah, and not be intimidated, or bribed by Hizbollah, as has been the case with the current UN peacekeeper force. Hizbollah refuses to accept this more robust force, and Israel will accept nothing less.
Although Israel has lost about fifty soldiers killed so far, this is a much lower loss rate than in previous wars. Better technology, weapons and medical care have all combined to reduce the casualty rate.
Hizbollah has no incentive to broadcast the extent of its injuries in the current war. The losses have been substantial. For example, Syrians have noted an enormous exodus of Lebanese Shia into Syria. Some 10-15 percent of Lebanon's Shia appear to have fled the areas of southern Lebanon and the Bekaa Valley, for refuge in Syria. They are not just getting away from Israeli bombs, but the rising possibility of another round of civil war with Lebanese Sunnis, Druze and Christians. Hizbollah is a terrorist organization, and for nearly two decades, other Lebanese have been on the receiving end of that terror. There are payback issues in play. Before Hizbollah attacked Israel, these issues were being worked out, but the deal involved Hizbollah disarming and giving up control of southern Lebanon. The Hizbollah militants didn't go for this, partly because they feared retaliation from Lebanese families they had terrorized (via murder, kidnappings or worse) over the last two decades. Better that all of Lebanon should suffer, than a few hundred Hizbollah thugs should pay for their crimes. The Lebanese know this, the Israelis know this, the international media ignores it. But it's these grudges that will destroy Hizbollah in the end. The Shia fleeing to Syria fear their fellow Lebanese more than they fear the Israelis.