Israel’s secret war on Hezbollah

On Monday, a secret Hezbollah munitions bunker in South Lebanon blew up under mysterious circumstances, injuring a senior official in the organization. This is the second such incident in recent months. The first occurred on July 14, when an explosion destroyed a major Hezbollah munitions dump in the South Lebanese village of Hirbet Salim. Hezbollah immediately pointed fingers at the Mossad. Whether or not Israel was to blame, the explosion caused Hezbollah considerable discomfort by proving that it was in flagrant violation of U.N. Security Council Resolution 1701, which forbids stockpiling weapons south of the Litani River.

The U.N. issued a strongly worded rebuke and sent representatives to investigate. But their efforts were thwarted by Hezbollah fighters, who, with the assistance of Lebanese troops, prevented the foreigners from examining the site. This caused further embarrassment to Lebanon, as it exposed the army's lack of neutrality and the active aid that it extends to Hezbollah.

The episode also led to heightened tensions on the Israel-Lebanon border. The specter of renewed fighting between Israel and Hezbollah looms as large today as it has at any time since the end of the Lebanon war in August 2006. Yet senior military officers in Israel's Northern Command are confident that the embarrassing outcome of the last round will not be repeated.

"By all means, let the Hezbollah try," one officer told me two weeks ago when I asked if he was concerned about the possibility of warfare. "The welcome party that we are preparing for them is one that they will remember for a very long time." That sentiment is shared by many of his colleagues.

The recent explosions have highlighted the weakened geopolitical status of Hezbollah, a diminishment which no one could have foreseen at the end of the last war. In 2006, on both sides of the border—and elsewhere in the Middle East—Hezbollah was seen as having triumphed. Not only was it able to withstand the vastly superior invading Israeli force, but it also inflicted heavy military casualties and brought civilian life in northern Israel to a standstill with its rockets. At the end of the war, a commission of inquiry was set up in Israel to investigate the military and political failure. A number of senior army officers resigned, and Israel's deterrence power was seen as having sustained a severe blow.

If the 2006 war underlined the military might of Hezbollah—a repeat, in a sense, of Hezbollah's success in driving out the Israeli occupying forces from South Lebanon in May 2000—it also forced Israel to include Hezbollah in any assessment of possible responses to an Israeli attack against Iranian nuclear installations.

As part of its combat doctrine, which eschews reliance on reinforcements and resupply, Hezbollah has stockpiled its weapons throughout Lebanon, but particularly near the Israeli border. According to current Israeli intelligence estimates, Hezbollah has an arsenal of 40,000 rockets, including Iranian-made Zelzal, Fajr-3, Fajr-5, and 122 mm rockets (some of which have cluster warheads) and Syrian-made 302 mm rockets. Some of its rockets can reach greater Tel Aviv. Hezbollah also has a number of highly advanced weapons systems, including antiaircraft missiles, that constitute a threat to Israeli combat aircraft.

But all is not rosy for Hezbollah. After the war, considerable dissatisfaction with the organization was voiced inside Lebanon. Many blamed its leader, Hassan Nasrallah, for Israel's retaliatory bombardments that caused widespread damage. Nasrallah stated that had he known Israel would respond as forcefully as it did, he would have thought twice before ordering the abduction of the two Israeli soldiers—the act that sparked the conflict.

Harsh criticism of Hezbollah also came from an unexpected source: Tehran. The Iranian strategy calls for Hezbollah to play two roles. One is to instigate minor border provocations. The other is to launch, on Tehran's command, a full-scale retaliatory attack should Israel target Iran's nuclear facilities. The 2006 war met neither criterion, and, as the Iranians complained, merely served to reveal the extent of Hezbollah's military capabilities.

Then, in February 2008, Imad Mughniyeh, the organization's military commander and Nasrallah's close associate, was killed in a car bomb in Damascus. The assassination of the man who topped the FBI's most-wanted list prior to Osama bin Laden was a severe blow to morale, as well as to Hezbollah's strategic capabilities. Nasrallah was convinced that the Mossad was responsible, and vowed to take revenge "outside of the Israel-Lebanon arena."

The Shin Bet, Israel's internal security agency, which is also responsible for protecting the country's legations abroad, has been on high alert ever since. But as of today, Hezbollah has not exacted its revenge. This fact was a topic of discussions at a high-level secret forum of Israel's intelligence services that took place from late July to early September.

Israeli officials raised four possible reasons for Hezbollah's failure to act, all of which reflect its current weakness.

First, no replacement has been found for Mughniyeh, whose strategic brilliance, originality and powers of execution are sorely missed by Hezbollah.

Second, Israel's intelligence coverage of Iran and Hezbollah is far superior today to what it was in the past. Planned attacks, including one targeting the Israeli Embassy in Baku, Azerbaijan, have all been foiled. The Israeli security services have warned Israeli businessmen abroad of possible abduction attempts by Hezbollah. They also shared information with Egyptian authorities that led to the arrest of members of a Hezbollah network who intended to kill Israeli tourists in Sinai. The arrest of these operatives resulted in sharp public exchanges between Egypt, Hezbollah and its Iranian masters, when Nasrallah admitted that these, in fact, were his men.

Third, Nasrallah cannot afford to be viewed domestically as the cause of yet another retaliation against Lebanon. Any act of revenge that he contemplates needs to be carefully calibrated. On the one hand, it needs to hurt the enemy and be spectacular enough to stoke Hezbollah pride. On the other hand, it cannot be so murderous as to cause Israel to respond with force. To complicate matters further, Israel has made it clear that because Hezbollah is part of the Lebanese government, despite the fact that the party that it backed lost in the recent election, any Hezbollah action against Israel would be viewed as an action taken by the Lebanese government. Thus Israel would regard Lebanese infrastructure as a legitimate target for a military response.

Finally, there are the Iranians. Their primary focus is on proceeding with their nuclear program without unnecessary distractions. Tehran's main concern is that a terror attack that can be linked to Iran would result in the arrest of its agents overseas, who are currently procuring equipment for its uranium-enrichment centrifuges.

Tehran has avoided direct involvement in foreign terrorism ever since 1996, when a group of Iranians were convicted in Germany of murdering political opponents of the Iranian regime. And unlike in the past (as, for instance, in the case of the 1992 bombing of the Israeli Embassy in Buenos Aires in retaliation for the assassination of Nasrallah's predecessor), it is now reluctant to place intelligence resources at Hezbollah's disposal. This is a serious blow to Hezbollah, which is not yet able to function as a full-fledged independent operational organization internationally.

Hezbollah is also clearly aware of the severe blow in terms of power and prestige that the Iranian mullahs suffered as a result of the massive protests following June's presidential election. Automatic support from Tehran is no longer a certainty. For now, at least, the Iranian hardliners have troubles of their own.

In short, despite the fact that Hezbollah today is substantially stronger in purely military terms than it was three years ago, its political stature and its autonomy have been significantly reduced. It is clear that Nasrallah is cautious and he will weigh his options very carefully before embarking on any course of action that might lead to all-out war with Israel. There are some experts in Israel who believe that even Hezbollah's retaliatory role in the Iranian game plan is currently in question.

Whether or not this is the case, all of this is being considered in Jerusalem as part of Israel's calculations about whether to strike Iran's nuclear facilities.

Mr. Bergman, a correspondent for the Israeli daily Yedioth Ahronoth, is the author of the "The Secret War With Iran" (Free Press, 2008).