Iran can break out to nuclear weapons "very quickly," and Israel must maintain operational readiness for any threat that may arise, Maj.-Gen. (res.) Amos Gilad, director of political-military affairs at the Defense Ministry, warned on Monday.

Speaking in Tel Aviv at a security conference organized by the Israel Defense publication and the Israel Artillery Association, Gilad said the security forecast was not sunny. "Today is a pleasant day. But there are clouds, and a storm, on the horizon," he said. "People don't believe it until it comes," he added.

Iran's nuclear weapons program remains the top threat to Israeli security, he said, describing the Islamic Republic as a "horrible regime" that threatens to exterminate Israel. He referred to a past statement by former Iranian president Ayatollah Hashemi Rafsanjani, who said that one atomic bomb would be enough to destroy Israel.

"They're determined to reach nuclear weapons. They want to get to a situation where [Iranian Supreme Leader Ayatollah] Khamenei asks [Ali Akbar] Salehi, [head of the Atomic Energy Association of Iran], can we develop nuclear weapons? And the answer must be yes we can. Not in English, in Persian," Gilad continued.

Iran's strategy is based on the twin goals of getting rid of choking international sanctions, and keeping the option of breaking out to nuclear weapons within "a few months," he said.

"President Obama keeps saying, and I think he means it, we won't tolerate Iran with nuclear weapons. Iran says, okay... we will build the infrastructure to get to nuclear weapons, including missile capabilities, scientists, etc. It's like a runner who can't jump two meters, so he builds a 1.95 meter ramp, and later he can jump from it and get to two meters. This is the greatest danger. There is a possibility Iran will achieve this. It's a potential existential threat," Gilad said.

He noted that Iran has overseen the construction of Hezbollah's arsenal of 100,000 rockets, and spent billions of dollars to build up Hezbollah's firepower, which threatens all of Israel's territory.

"This is a military threat, not a terrorist one," he said, adding, Israel has "not been successful in preventing a buildup [of rockets] in Lebanon." Alleged Israeli action to prevent Hezbollah's armament program, as mentioned by foreign press reports, is the exception, Gilad said.

Iran's Revolutionary Guards Corps has global command centers for terrorism that are located "everywhere," and planned to "slaughter dozen of Israelis over Passover in Thailand," the senior defense official said. These efforts are "mostly failing," he added.

"Can you imagine nuclear bombs in Iran's possession, and how this will destabilize the region?" If the July 20 deadline for nuclear talks between the international community and Iran is delayed, this would be "excellent for the Iranians, as they want to stop the momentum of sanctions," he added.

Israel must maintain operational readiness, and never knows "when some threat will come," Gilad stated. He praised the country's defense industries for building up a shield against ballistic missile threats, and paid tribute to "unbelievable" intelligence achievements vis-a-vis Iran.

Turning his attention to the Palestinians, Gilad said that should Palestinian Authority security forces take exclusive control of West Bank, there would be a "very high feasibility" of rockets and shelling raining down on greater Tel Aviv.

Gilad expressed skepticism over the chances of Hamas and Fatah achieving real unity, rather than an "image of unity," adding, "I cannot imagine them reconciling. Hamas is determined to take over the PLO. Their strategic plan has never changed, to take over whole of the Middle East, and they don't mind starting in Ramallah."

Addressing the situation in Syria, Gilad said that two al-Qieda organizations, terror groups "without limits," are operating over the northern border, and include 1500 European or foreign passport holders fighting in Syria. "Sooner or later, they will carry out a spectacular terrorist attack in Europe or Israel." Israel has beefed up defenses along the northern border, but the Syrian crisis is also "putting pressure on Jordan," he warned.

"Al-Qaida is new in our neighborhood. It is [now] in Lebanon, Syria, and it is trying but failing to attack Jordan and Israel. In Sinai, it is extending capabilities to Cairo to be able to murder [the Egyptian] president. Either it defeats you or you defeat it."

Israel today "can defeat any combination of enemies," Gilad said, but the moment Iran goes nuclear and triggers an Arab nuclear arms race, the region will become "hell," he said.