The events of this week unfolded at a dizzying pace for senior officials in the defense establishment. There were the full-on preparations for the enlistment of ultra-Orthodox men in the wake of the collapse of the national unity government; the visit of senior Obama administration officials for talks on the Iranian nuclear program, and the efforts to reach an agreement on the major points of a multi-year budget.

All of these were just the appetizer for the two-pronged drama that hit us on Wednesday: the attack that took out key senior members of the Syrian defense establishment, and the attack on the Israeli tourist bus in the Bulgarian resort town of Burgas.

These two events jolted Israel’s focus back to the northern front. Not that we ever stopped focusing on it — the Syrian uprising has required daily monitoring for over a year now. But the constant trickle of rocket fire from Gaza, the foothold gained by terrorists in the Sinai (and the constant stream of job-seeking migrants from that area), and the headache that is Iran, diverted attention to other areas. As long as President Bashar al-Assad remained in power in Syria, the headache was a relatively minor one. By extension, Hezbollah was a fading nuisance, despite the marking last week of the six-year anniversary of the Second Lebanon War.

Two days ago, in one fell swoop, we crashed back to reality. The signs were there for months, indicating that Assad’s days in power were numbered. Somehow, though, people grew increasingly convinced that it would take more time. Maj. Gen. Aviv Kochavi, the head of Military Intelligence, told the Knesset on Tuesday that the regime in Syria would be toppled in anywhere between “two months and two years.”

Just 24 hours later, we were reminded how fragile a concept time is in the Middle East. The deaths of senior members of the Syrian defense echelon signaled that the collapse of the regime could come quicker than anticipated.

As of Thursday, experts were struggling to come to agreement over the question of whether we are “at the beginning of the end,” or “the middle of the end.” On one issue, there is total agreement: Assad will fall. He has bled so heavily over the last 16 months that he has now passed the point of being able to recover.

It all began when his opponents stopped fearing him. The anti-government protests which started in the rural villages spread to the larger cities, until they finally reached the heart of Damascus. The situation was compounded by a wave of desertions. The climax came two days ago, when an assailant managed to reach the president’s inner circle and, more importantly, knock off officials important to the regime, especially Assef Shawkat.

Israel has closely followed Shawkat's escapades over the last few decades. His determination as a soldier and a commander who led troops during the massacre in Hama in the early 1980s endeared him to the Assad family. His cunning and guile won him the heart of then-President Hafez Assad’s oldest daughter, Bushra, despite her father’s initial resistance to the relationship. But the moment the uprising began, there was no doubt that he was the right man “to deal with” the violence. As the man who commanded the violent oppression of the Hama uprising in the early 1980s, Shawkat had nary a doubt as to the best way to handle the current situation: with force.

It may not have been reflected in his official title, but Shawkat was for all intents and purposes the second most-powerful man in Syria. He is the one who oversaw the government campaign against the opposition forces. He is the one who gave out orders to the army, he is the one who ran the day-to-day affairs of the various security and intelligence apparatuses, and he was responsible for coordinating key strategic matters like procuring arms from Russia.

Shawkat’s assassination is a body blow to Bashar Assad. Not only is he now lacking a commander and someone to coordinate between agencies, but the most fearsome member of his inner circle has also disappeared. As if that were not enough, the successful operation (which also killed other officials) had another important accomplishment: The rebels succeeded in penetrating the president’s most intimate circle. From this point on, Assad will have to think twice about the people who are closest to him.

It is therefore hardly surprising to read some of the reports circulating on the Internet that members of Assad’s family have already secretly fled to Russia. The Assad family has been guaranteed asylum in Moscow. As of Thursday morning, it appeared that they had not yet left Damascus.

In Israel, officials are adhering to the wise choice that they made at the start of the tumult – no involvement as long as the events do not affect us. On a tactical level, the military has beefed up its defensive alignment along the Israeli-Syrian border atop the Golan Heights in a bid to fend off the double threat of a possible terrorist attack and an influx of refugees. Intelligence monitoring has also been stepped up. From a strategic standpoint, Israel has been careful to remain on the sidelines so as not to give Assad an excuse to open fire.

Now, with his downfall imminent, the headaches begin. There are the tiny headaches, like the possibility that the Golan Heights will turn into a northern Sinai Peninsula: a strip of land that is beyond government control and becomes a base of operations for terrorism. And there are the larger headaches, such as the prospect that the Syrian authorities lose control of its arsenal of strategic arms.

In recent weeks, Assad has utilized the services of Hezbollah agents and Iranian Revolutionary Guards officers who have physically protected these assets. The regime is fearful that these weapons could fall into rebel hands. When Assad departs, these two organizations will have to take an immediate decision. They will have to decide whether to leave these weapons in Syria, which would spare them a confrontation with Israel but there will still be a possibility that opposition elements could eventually get their hands on them. Or they could arrange to move them west, to Lebanon, which is a much more stable and where Hezbollah is virtually unchallenged – except of course by Israel, which would launch military strikes in this scenario.

The Israeli dilemma may well necessitate a decision soon. It would be purely based on intelligence – what weapons are being transferred, in what quantities, and do we know enough to ensure a direct hit. Israel will also base its decision on a much broader situational assessment, which would ostensibly take into consideration factors like the distant repercussions of an attack (on the Iranian nuclear program), the immediate ramifications (the reaction on the Egyptian, Palestinian, and Jordanian streets), and the domestic implications (the defense of the home front).

The same logic which dictates that Israel must not allow weapons of mass destruction to fall into enemy (Iranian) hands — not just out of fear that it will use them against us but also so as not to fundamentally alter the balance of power and deterrence between the two sides — should also be applied to terrorist organizations (Hezbollah) who seek to gain possession of their own, unconventional arms.

Even if Hezbollah fails to get its hands on the coveted merchandise in Syria, it still boasts 60,000 missiles and rockets that are capable of hitting any point in Israel. Chemical and biological weapons would give the organization a military capability that few countries in the region can boast. Coupled with its gall and ideology, Hezbollah, a jihadist group that does not always act logically, will pose a formidable – if not, impossible — challenge to Israel.

As such, Israel made it clear to Hezbollah, as well as to Western countries, that the transfer of strategic arms to Lebanon would be tantamount to a declaration of war. Officials identify four key weapons systems that are piquing their concern: chemical and biological agents, advanced anti-aircraft systems, long-range missiles, and advanced land-to-sea missiles.

It is uncertain whether moving these arms westward would necessarily lead to war, but one should not be fooled. Ever since the Second Lebanon War, the north has experienced six very quiet years. Theoretically, there is no reason that the calm and quiet should not continue. In reality, however, things could heat up quickly.

It will not happen as a result of the terrorist attack in Burgas. Despite the anger and the desire for revenge, Israel will not respond from the gut, but from the head. If it does embark on a military campaign in Lebanon, it will not be to settle scores. Rather, it will serve a strategic purpose, namely preventing Hezbollah from becoming stronger.

It seems as though Israel knows for certain that Hezbollah is responsible for the killing of Israeli tourists in Bulgaria, but it may not. As of Thursday, there was no definitive, unequivocal proof linking the explosives used in the attack to Iran or Lebanon.

But there are plenty of logical indicators that would lead to such a conclusion. For more than four years, Hezbollah has been trying to avenge the assassination of its top military commander, Imad Mughniyeh. It is hesitant to do so directly to avoid provoking all-out war, so instead it seeks “softer” targets, like a senior official, a foreign embassy, or tourists.

Israel's defensive effort has been strong enough and effective enough to Hezbollah’s designs abroad. Iran's attempts to contribute to this effort have been met with an impressive response, save for the bomb attack which wounded the wife of an Israeli diplomat in New Delhi. Still, observers and analysts knew that it was just a matter of time. The determination to pull off an attack was there, and there was just too much ground to cover, too many targets available.

Earlier this month, we were informed that terrorists were apprehended in Kenya and Cyprus. Bulgaria slipped in under the radar. We need to wean ourselves off the expectation that the security forces will always be there to protect us, wherever we go. Israeli intelligence will certainly investigate where it could have done more (in January, authorities issued a travel advisory for Bulgaria which was later canceled) and more importantly see where it can improve. No one in Israel has any doubt that Hezbollah will strike again.

Quickly solving the Burgas attack will help prevent the next round. Not only will authorities be eager to ascertain the means used in the attack – including the type of explosive, the trigger mechanism, the identity of the bomber and co-conspirators, and the manner in which they entered and exited Bulgaria – but they will also want to be able to point the finger of blame at Iran’s Supreme Leader Ali Khamenei and Hezbollah Secretary-General Hassan Nasrallah.

This is key to the issue of battling terrorism, and is critical when it comes to upping the pressure on Iran’s nuclear program. Despite the plumes of smoke that billowed in the skies of Burgas and Damascus, the Iranian drive for a nuclear bomb remains the most central, weighty, strategic issue preoccupying the Israeli government.

The clock continues to tick and Iran is moving forward, albeit slowly, and it is doing so with determination. It is approaching the point at which it will be difficult to stop it. After the diplomatic effort to halt the nuclear program failed, the ultimate dilemma remains: Allow a nuclear bomb, or bomb Iran? Alongside these considerations, there is also the issue of timing. The Americans are desperate for us not to attack before the presidential elections in November. To this end, they are dispatching whoever they can to the region in the hopes of extracting assurances that we will not go crazy.

Among our top officials, nothing has changed. Those in favor of an attack and those who oppose remain entrenched in their positions. What has changed is the regional calculus. There are those who view this as a positive development (over time, it has been proven that with the right amount of force, regimes do fall, and the same will happen with Iran). But the immediate debate that will be waged here in the coming weeks and months will be different: Should Israel attack and deal with the consequences? Or should Israel refrain from attacking for now and deal with the consequences?

Everyone knows the consequences, and they do not need to be listed here. What has changed is the situation. A war in Lebanon over the transfer of chemical and biological weapons or anti-aircraft missiles batteries would place Israel’s focus northward while making the prospect of an attack on Iran more remote, perhaps for an extended period of time. Failure by Israel to attack in Lebanon would mean living with unprecedented danger in the north and putting the security of the country at an irresponsible risk.

On the other hand, if assessments are correct, and an attack on Iran would probably result in a war against Hezbollah, perhaps it would be best to kill two birds with one stone. Perhaps Israel would be best served by initially targeting the Iranian nuclear program, and then along the way take out Hezbollah’s capabilities.

Such a maneuver would require time that Israel may not have (Assad could very well disappear within days), and the consequences would be severe. It is unwise to take action in Iran in order to strike at Lebanon. There is also the possibility that the move could backfire, setting Israel on a collision course with the West and the Arab world. Israel would be risking failure, and in the process strengthen Iran, with its nuclear program still intact.

These headaches, which intensified this week, will require a remedy, and soon. In the meantime, the word in Israel is that officials are “monitoring" the situation, and even "with concern,” in the hope that threats and deterrence from our side and chaos and logic on their side will win out and prevent an escalation.

Will this succeed? It may not. If there is an escalation Israel will be required to act to thwart this prospect, though ideally it hopes to do this in a way that would stunt Hezbollah's growth and at the same time prevent the outbreak of all-out war. This is a very dangerous game, with serious risks. It is not recommended for the faint of heart.

Whoever thought that Wednesday was the hottest day of the year should reassess their conclusions. These next few weeks could get very intense, on all fronts, with a ferocity that we haven’t seen thus far.