The defection of the Syrian prime minister indicates a new climax in the war in Syria. While the Israeli press has been focusing its attention on a potentially nuclear Iran, a crisis situation has developed in Syria under our very noses.

Before the outbreak of the Syrian uprising, a stable central regime had been upholding an agreement with Israel achieved throughout the cease-fire negotiations after the Yom Kippur War. A part of this pact had been the unwritten understanding that non-conventional weapons would not be used in the foreseeable future except in the case of existential risk.

For decades Israel has not considered Syria a serious threat; for nearly 38 years Jerusalem has trusted Hafez Assad and his son to refrain from using chemical and biological weapons. But in recent weeks the issue of non-conventional weapons has grabbed center stage. Moving Damascus’s arsenal to unknown storage facilities, transferring it to the Hezbollah terror organization, or letting it be captured by the rebels are all terrifying possibilities. Another option is that the Syrian regime, which is close to a state of existential danger, will direct these weapons against Israel.

Syria’s long-time investment in development and production of a non-conventional arsenal and surface-to-surface missiles, along with its maintenance of an old air force, may pay off. A few missiles or aircraft armed with chemical or biological weapons may cause moderate physical damage — but its effect on morale would be enormous.

One conclusion to be drawn at this stage is that the Syrian threat is just around the corner, and its capabilities are far more dangerous than those of Iran. How to deal with it? The approach that says the Iranian threat should be addressed by focusing on its nuclear industry may be the right strategy against Syria, whose military abilities are much broader.

Israel’s security systems regarding Syria are defensive by nature. But it is impossible to build a fool-proof defensive shield against an integrated force of non-conventional weapons, missiles and attack aircraft. Consequently, Israel should complement its defense with offense by preparing to attack and destroy Syria’s non-conventional power before it is activated.

The paradox is that as Syria is weakening due to its internal war, it becomes a more significant threat to Israel. The combination of non-conventional weapons, missiles and aircraft presents challenges which require Israel’s eyes to be wide open.

Pinchas Sapir, a politician in the state’s early decades, said his trust in David Ben-Gurion was such that he followed him with his eyes closed — but occasionally he opened one eye to make sure that Ben-Gurion’s were open. In the same vein: trust the IDF but nevertheless at this juncture Syrian challenges and responses should be discussed.