In recent months Hezbollah, with encouragement and perhaps even pressure from its Iranian patrons, has been ramping up its participation in the Syrian civil war. Iran's considerations -- which are identical to those of Hezbollah leader Hasan Nasrallah -- are obvious: If Bashar Assad's regime falls in Syria, Nasrallah will go down with him, leaving Iran as the next target of the "unholy alliance" between the West and Israel, or so they fear in Tehran. Thus Iran feels compelled to do everything it can to help Assad stay in power.
Hezbollah's actual manpower contribution to Assad is not huge. In Syria 200,000 soldiers are fighting an army of 100,000 rebels. A few thousand Hezbollah fighters cannot really turn the tide. Nonetheless, these are well trained and highly motivated fighters who made the difference in several important battles throughout Syria.
In recent weeks the momentum of the fighting has shifted, and the Assad regime has slowly made gains in suppressing the rebels. While not a dramatic change in Syria's bloody civil war, it is still the first time since the uprising began that momentum is actually on Assad's side.
But Hezbollah and Iran's involvement in Syria's war comes with a price, even a heavy one. Barely a day goes by that Hezbollah is not burying one of its fighters killed in Syria. Add to that the recent terror attacks by Sunni extremists against Hezbollah strongholds in Lebanon and against Shiites within Syria, as well as Tuesday's attack on the Iranian embassy in Beirut. Tuesday's attack marked the first time suicide bombers were used against Hezbollah, which itself has not hesitated to use the same "weapon" against its rivals.
In Lebanon people talk about the "Syrianization" of the country. Al-Qaida-inspired groups like the Nusra Front and the Islamic State of Iraq and the Levant are calling to bring Syria's fighting into Lebanon and employ the terror tactics used in Syria.
With Hezbollah's involvement in Syria's fighting going on as long as it has, it was only a matter of time before the rebels in Syria decided to enact revenge on the group and its supporters in Lebanon. It is likely that the terror attacks in Lebanon will continue. Most Lebanese want to avoid their neighboring country's violence seeping into their own. But radical Lebanese Sunni Islamist groups have their own agendas, and want to get Lebanon involved to be able to conquer Syria and Lebanon and spread their influence. This is one of the reasons why they tried to attack Israel in the past, in hopes of dragging it into a conflict with Hezbollah.
In the shadow of the Syrian civil war Lebanon has begun itself to slip into the Sunni-Shiite battle. Some Lebanese Shiites have dared to question Nasrallah's decision to drag them into Syria's fighting. In Tehran too, a different tune is being sung, and it is possible that breakthroughs in the nuclear talks will lead Iran to re-evaluate the merits of being bogged down in the Syrian-Lebanese mud. Until then suicide bombers will continue to detonate at Iranian and Shiite sites in Lebanon.