TEL AVIV – Israel's top Air Force officer on Tuesday praised the "revolutionary" operational potential of its new fifth-generation fighter – the F-35 Adir – yet warned that growing anti-aircraft threats could mean that part of its fourth-generation force could be downed in combat.

Speaking at the annual conference of Israel's Institute for National Security Studies (INSS), Maj. Gen. Amir Eshel, IAF Commander, singled out Russian-deployed S400s in Syria, which he said "brings critical capability" that could challenge Israeli operations in the region.

"Clearly we will encounter threats we never encountered before … in the air and from the ground," Eshel said of the S400 and a spectrum of other threats posed by regional states and non-state actors.

"From all those threats, yes, there will be an ability to thwart part of the activities of the IAF. I don't delude myself. We are preparing ourselves so this interference is kept to the bare minimum … but part of our activities will be thwarted. That's clear. Part of our planes will fall. That's clear. That's part of war, but [these threats] will never be able to stop us," Eshel said.

As for the F-35, the first pair of which were delivered into IAF hands last month, Eshel said the US-produced stealth fighter will lift the rest of Israel's fourth-generation frontline force of F-15I and F-16I fighters into the next generation and preserve its air power supremacy for decades to come.

"It's more than just an aircraft. It will transform the entire service into a much more effective, much more lethal force," Eshel said.

"We are not adapting the F-35 to the IAF. That would be a mistake. Rather, we're adapting the IAF to the F-35. We'll learn how to do this so that all of the force will rise to the fifth generation," he said.

Israel's top air force officer said he was undeterred by criticism directed at the F-35 program, and that the return on investment was well worth the cost.

"There's a lot of criticism that this doesn't work and that doesn't work. But whoever has a smart phone knows that software changes all the time. This is a smart plane, and there will be different upgrades and versions. … What's important is that it will know how to operate in places that nothing else can, with a very high level of effectiveness across the spectrum of threats and operational scenarios."

In an address devoted to the singular attributes of airpower, Eshel said the F-35 embodied flexibility, speed, agility and survivability that has become a central element of Israeli force strength. "It's a revolution; far better than anything we have and anything that is flying in this region," he said.

According to the IAF commander, Israeli airpower must be prepared to operate in multiple domains, from anti-terror threats close to home to more advanced threats in neighboring states all the way to strike and intelligence collection operations conducted "thousands of kilometers away."

"The air domain allows us to deal with a spectrum of threats near and very far away," he said.

Eshel insisted that no other tool of military power, whether it involves cyber, special ops or land and sea forces, is equipped to deal as effectively as airpower, especially when fighting in three theaters simultaneously.

"The Israel Defense Forces demands that we be prepared to fight in three theaters simultaneously …. Our air assets can be in the northern theater in the morning, in places much farther away in the afternoon, and in the evening, operating in Gaza. That's what's demanded and there's no other force that can do this but airpower."

In his address to the INSS audience, retired US Air Force Gen. Gary North, vice president for customer requirements at Lockheed Martin, also cited threats posed by Russian S400s in Syria and the benefits of operating the F-35 in a high-threat environment.

"The combination of stealth and sensor fusion – from space and other airplanes – gives the individual aviator in the cockpit information and allows him or her to share it with others flying in formation and other airborne platforms and to disseminate it all down to command and control facilities on the ground," North said.

Israel's F-35 Adir force, said North, provides strategic deterrence as well as the ability to enjoy freedom of movement not provided by the very best of fourth-generation aircraft. "The Adir uses stealth to get very close and to enable operational decisions as to whether to engage or disengage."